really a "truth universally acknowledged." Instead, this opening line is a perfect example of sarcasm, or verbal irony, and a perfectexample of Austen's wit.
Situational irony describes a moment when something occurs and the exact opposite was expected to occur. Either the audience or the characters can have the opposite expectations. One instance of situational irony can be seen early on in the novel at a party that takes place at Lucas Lodge. After Elizabeth is asked to play and sing, the party begins to dance. At the same moment that Sir Lucas is trying to convince Mr. Darcy to join in the dancing, Elizabeth begins walking towards them. Mr. Darcy so adamantly protests dancing to Sir Lucas, even insulting the activity, saying, "Every savage can dance," that when Sir Lucas sees Elizabeth and encourages Darcy to dance with her the reader as well as Elizabeth are very surprised when Darcy "requested to be allowed the honour of her hand" (Vol. 1, Ch. 6). Darcy's behavior in this instant is a true reversal of his earlier behavior, especially at the Meryton assembly. Hence, this is a perfect example of situational irony. In addition, the moment is also amusing due to the sudden change of behavior, also making it another example of Austen's wit.  
Dramatic irony occurs when the reader is aware of something that the characters have no idea of. This scene is also a fine example of dramatic irony. The reader has already begun to get the impression that Darcy feels an attraction for Elizabeth, which the reader began to see when she was tending to her sister at Netherfield. Therefore, the reader knows that Darcy's sudden interest in dancing with Elizabeth is actually genuine while Elizabeth still believes that he dislikes her and is merely asking in an attempt to be well mannered. Again the situation is amusing due to both Elizabeth's and Darcy's reactions to the situation. Hence, again, this use of dramatic irony also demonstratesAusten's wit.

From the very first pages the narrator's delight in making ironic, witty comments about her chararcters is clear. Frequently these come through the mouthpiece of Lizzy Bennet, but they also are common occurences from the omniscient narrator. To give just one example, Lizzy Bennet employs a rather cruel form of irony to describe Miss De Bourgh on her first meeting:

"I like her appearance. She looks sickly and cross. Yes, she will do very well for him."

In this example of irony we need to possess knowledge about matters exterior to the context in order to detect and fully appreciate the irony. Here, obviously Lizzy does not like the appearance of Miss De Bourgh - her "liking" is only based on her dislike of Mr Darcy and his and Miss De Bourgh's intended union. Such use of verbal irony, or saying the opposite of what is really meant, is used throughout this novel, but the reader must be aware of the wider context in order to detect and enjoy the uses of irony.

Irony definitely extends beyond the verbal in this novel however. It is highly ironic that Mr. Darcy, having just persuaded Mr. Bingley to abandon his pursuit of Jane Bennet, then goes on to propose to Lizzie Bennet, in spite of exactly all of the same objections standing against such a union. Likewise, Lady Catherine's visit to Lizzie Bennet to try and prevent the union of Darcy and Elizabeth, unknowingly and highly ironically, is a key event that brings her nephew and Lizzie Bennet together.

That is enough to get you started - you might also want to think about the kind of irony employed by various characters, and indeed, the narrator herself. Linked to this you will want to examine the characters irony is used against and their awareness - or not - of the irony that is employed against them.  For example, Mr. Bennet frequently employs irony against his wife and also Mr. Collins, who are blissfully unaware of the double meaning.

In Pride and Prejudice, wit is the allure of the narratorial voice and irony is the lens through which the errors, transgressions, foibles and follies of the characters are seen and the brush with which their lives are drawn. Wit in the 18th and 19th centuries (even though Jane Austen's first and subsequent novels were published in the 19th century, they were written in the 18th century) encompassed a larger idea than humorousness. Wit entails a great intelligence, one that can express ordinary observations with an original insight born of mental acuity and one that see the differences between what is expected and what is actual and can find and convey the ironic mirth in the comparison of the two.

Jane Austen's gift is for witty irony. She has the ability to drawn on her small piece of "ivory" true to life characters, complete with all their flaws, who are beloved to Austen's readers precisely because they are seen truly with their good and their bad...with certain exceptions. However, even the unlovable exceptions like Mr. Collins and Lady De Bourgh are revealed under the light of irony with such a delicate hand that they aren't wholly despised.

The opening line of Pride and Prejudice is the most oft quoted example of Austen's witty irony. She says: "It is a truth universally acknowledged that a single man in possession of a good fortune must be in want of a wife." The wit is most evident in the words: "It is a truth universally acknowledged...." For one thing, universal truths are usually very large ideas that are very serious and very important. To think of rich bachelors "wanting" wives in that context is always worth a chuckle. The irony is most evident in the idea that wealthy single men are in search of wives. In truth, it is probably universally acknowledged that wealthy single men are the last ones to go looking for wives.

Wit in Pride and Prejudice provides intelligent glimpses into human nature and life choices through original juxtaposition of ideas and astute observations. Irony in Pride and Prejudice presents human truths and realities through situations, beliefs and narratorial observations that shows an opposing reality to what is expected to more clearly enlighten what is actual.

The best way to discuss Austen's use of humor and irony would be to name a couple of different examples. Although, it should be noted that when looking at Austen, it is often difficult to treat humor and irony separately since for the most part she uses irony to create her humor.

We can certainly see many examples of Austen's humor in the character Elizabeth due to her quick tongue and ready wit. One of the best examples of Elizabeth's wit takes place the time she stays at Netherfield to look after her sick sister Jane. One evening while Miss Bingley is playing lively Scottish music on the piano, Darcy turns to Elizabeth and asks if she feels like dancing a reel. Elizabeth gives a very witty reply with the intention of making Darcy look like a fool in his pride when she responds by saying he only asked her that so he could insult her taste and, therefore, will not permit him to do so, as we see in her lines:

You wanted me, I know, to say "Yes," that you might have the pleasure of despising my taste; but I always delight in overthrowing those kind of schemes ... I have therefore made up my mind to tell you that I do not want to dance a reel at all--and now despise me if you dare. (Ch. 10)

Not only are these lines witty, they can also be seen as an example of verbal irony. Verbal irony is when the speaker says the exact opposite of what he/she means, often sarcastically. These lines are most definitely spoken with sarcasm. Not only that, it's probably untrue that Elizabeth does not want to dance a reel; she would probably very much enjoy dancing a reel, but is only saying what she says to insult Darcy.

Another example of Austen using verbal irony to create humor can be seen in the very opening lines of the book:

It is a truth universally acknowledged, that a single man in possession of a good fortune must be in want of a wife. (Ch. 1)

This example of verbal irony applies to the narrator as it is the narrator who is speaking sarcastically. The irony is that it is only mothers and daughters who believe a wealthy man "must be in want of a wife." The men themselves probably give it little consideration, preferring instead to enjoy their freedom and their wealth by themselves. Therefore, the opening line does not state a "universally acknowledged truth" at all, but rather a notion held by mothers and daughters. Hence, the opening line says the exact opposite of what the author/narrator really means.

I have always enjoyed the witty opening of Pride and Prejudice.  From the first sentence, the book pronounces both its subject and its tone.

The very first line in the book is a joke about marriage.

IT IS A TRUTH universally acknowledged that a single man in possession of a good fortune must be in want of a wife. (ch 1, p. 4).

With this sentence, Austen sets the tone for the book—biting but witty—and the subject—marriage.

The sentence introduces the elements of the relationship between husband and wife, especially in terms of spending money.  The conversation between Mr. and Mrs. Bennet is also quite humorous, poking fun at the marital relationship.

Mr. Bennet made no answer.

“Do you not want to know who has taken it?” cried his wife, impatiently.
“You want to tell me, and I have no objection to hearing it.”
This was invitation enough. (ch 1, p. 4).

The stereotype presented in the first line, that women spend their husbands money, is further developed to the idea that women talk too much, and care about money and status, and men just humor them.

Thus, from the beginning we know that Pride and Prejudice will be a book about marriage, relationships, and finding humor in them!

Jane Austen provides insightful social commentary combined with humor and genuine affection for human beings, because of and despite our countless foibles. Through the combination of understatement in her prose and exaggeration in the scenarios and characters’ behavior, she gently but steadily mocks the upper-class and upper-middle-class society on the fringes of which she lived. Her dim view of the power of society to influence behavior negatively is confirmed throughout.

Although Pride and Prejudice is primarily concerned with marriage, the fact that its title focuses on the personal and social factors that generally impede marriage already shows that the author will take a critical stance. At the broadest level, the fact that the Bennets have five daughters initially establishes an avenue for Austen’s critique. The Bennet family must find suitable—meaning well-to-do—husbands for at least some of their daughters; the family cannot afford to provide for them all, and proper ladies do not work. Through Mrs. Bennet’s normal state of near-hysteria, the author expresses very extreme views of proper marriage, combined with the very real concerns of all respectable parents. Mr. Bennet offers the contrasting side of impractical idealism, as he withdraws rather than face the reality of the family’s situation.

Locating Lizzie and Darcy at the center, the author shows that strong-willed, intelligent people can make a difference but still are bound by social conventions. Pride is a flaw that both characters share, however, which initially impedes them not only from finding personal happiness but from helping those around them. Although Lizzie believes herself exempt from social prejudice, even as the novel’s protagonist she is far from immune from the author’s satirical touch. Her hypocrisy, though short-lived, is most evident in her cruelty toward Charlotte upon her engagement to Mr. Collins. Only after Lizzie faces the importance of their friendship and treats her kindly does she herself become worthy of a good marriage.

Nowhere is Austen’s keen insight more evident than in her treatment of Wickham and Lydia. Although Wickham is a scoundrel who tricks the underage Lydia into eloping with him, intending to blackmail her parents, everyone realizes they must marry. The repercussions of the elopement, as Mr. Collins so harshly reminds the Bennet girls, are the ruin of all their marriage prospects. Mr. Darcy shows himself an honorable man by paying Wickham and his creditors so that the couple can be married. Darcy is revealed as a truly noble person, which radically alters Lizzie’s opinion of him. However, not only the two of them but also everyone around them is bound by the deeply problematic social conventions that decree marriage to be the only acceptable solution. The reader fully realizes that the foolish Lydia and the reprehensible man will be miserable together, Austen resolves the problem by exiling them to the north, away from the other sisters. This ending enforces her satirical intent, as none of the characters’ actions improve society at all but rather reinforce its power over even those who disapprove of it.

Pride and Prejudice is considered one of Jane Austen's most comical works, and the humorous element of satire is conveyed throughout. Satire was a vehicle for which Jane Austen could demonstrate her own views on society. The novel conveys Austen's disapproval of how individuals view public opinion to be superior over all other opinions, in the absence of details and facts. One of the most salient instances of satire in the novel occurs when Darcy presents himself at the ball.

Mr. Darcy drew the attention of the room by his fine, tall person, handsome features, noble mien; and the report which was in general circulation within five minutes after his entrance, of his having ten thousand a year. The gentlemen pronounced him to be a fine figure of a man, the ladies declared that he was much handsomer than Mr. Bingley.

The ladies at the ball view Darcy as more attractive than Mr. Bingley by virtue of Darcy's grander income. Note that the men in the room almost immediately pronounce Darcy to be a great man, simply because he is wealthy—before his pridefulness and arrogance becomes apparent.

Satire is also contained within individual characters. Mr. Collins is preoccupied with how he is perceived by society, and his main objectives in life are to gain more wealth and prestige. His character functions as a stereotype by which Austen comments on Georgian society. Collins believes he is a superior match due to his rank in society, whereas Elizabeth and the readers know he is an overly conceited, pompous, and foolish man. Similarly, Austen conveys the equivalent stereotype of women in society who are preoccupied with wealth and social climbing with Mrs. Bennet, who is obsessed with finding rich men to marry her daughters to. It is quite funny when Mrs. Bennet gets so worked up about the prospect of rich men that her nerves overwhelm her.

Jane Austen's humor is witty and sarcastic, a mix of both obviousness and subtlety. It is important to note both the societal context in which her novels are written and the many nuances of comedy itself, which is conveyed differently across genres and time periods.

Certainly Mrs. Bennet is a source of humor for many. Her sheer ridiculousness and complete lack of self-awareness often renders her an object of horror for her two eldest daughters, but she is a font of hilarity for readers. The narrator describes her as having a mind not so "difficult to develope. She was a woman of mean understanding, little information, and uncertain temper. When she was discontented she fancied herself nervous. The business of her life was to get her daughters married; its solace was visiting and news" (Volume I, Chapter I). She is often oblivious to the social errors she commits, and even when she is not, she doesn't care enough to stop. Mrs. Bennet is basically an older version of Lydia, past the dangers associated with Lydia's age. She is vapid and silly.

Mr. Collins is yet another source of humor. He "was not a sensible man," though he had "a very good opinion of himself [....]  [H]is authority as a clergyman, and his rights as a rector, made him altogether a mixture of pride and obsequiousness, self-importance and humility" (Volume I, Chapter XV). His combination of proud haughtiness with his desire to flatter his social superiors, his high opinion of himself mixed with his ability to lower himself when called for in society makes him as ridiculous as Mrs. Bennet. He is constantly comparing everything to Rosings Park, his patroness's home, discussing the fixtures in that home along with their size, price, and so on. He is eager to make peace with the Bennets by choosing a daughter to marry, and when Mrs. Bennet informs him that Jane is taken, he quickly switches his affections to Elizabeth. His proposal to her is both insulting and absurd, and it is -- in large part -- hilarious and cringeworthy because he doesn't realize it.

Put the two together at the Netherfield ball, add Mary Bennet (with her eager desire to showcase her small talents) and Mr. Bennet (with his inability or unwillingness to abide by social convention), and we have the recipe for a horrifyingly hilarious scene. First, Mrs. Bennet speaks loudly about "her expectation that Jane would be soon married to Bingley" and how that "must throw [the other daughters] in the way of other rich men"  (Volume I, Chapter XVII). Then Mary leaps up "after very little entreaty" to play the piano for the company: "her voice was weak, and her manner affected. -- Elizabeth was in agonies." She sings a second song (which she ought not to have done), and Mr. Bennet jumps in and insists that she give "the other young ladies" an opportunity "to exhibit." His unfortunate word choice is likewise humiliating. Then, in the awkward silence which ensues, Mr. Collins stands up and begins an elaborate speech on the pleasures of music. "Many stared. -- Many smiled." This was neither the time nor the place for this conceited little man to wax philosophic about the subject of music; it was the time to actually have music. "To Elizabeth it appeared, that had her family made an agreement to expose themselves as much as they could during the evening, it would have been impossible for them to play their parts with more spirit, or finer success."

Through characters and scenes like this, we can find a great deal of humor. As Mr. Bennet says, "'For what do we live, but to make sport for our neighbours, and laugh at them in our turn?'"

Pride and Prejudice is a satire on marriage because it presents five different couples with different reasons to marry, and the outcome of each couple is directly proportional to the reasons why they got married.

This being said, what Austen was trying to do was to show how much pressure society would place on women to attain a good marriage, because this was the only way they would make any gains in life in general.

Therefore, all the marriages that began for all the right reasons, ended up correctly. Those which began in chaos, ended the same way.

Jane Austen is satirizing the institution of marriage as it was considered in her day.  In 1800 England, many women married, not for emotional or romantic intentions, but for social and economic security, and this caused a bit of dissatisfaction.  Austen is clearly critical of a society where it is nearly impossible for women to be financially independent, and who are therefore forced into marriages for convenience.  This is most clearly evidenced by the marriage of Charlotte Lucas to Mr. Collins.  Charlotte very early in the novel tells Elizabeth that love in a marriage isn't important to her, so her marrying the rather annoying Mr. Collins doesn't come as that big of a surprise.  If Charlotte had not married, she would have been destitute, so she makes the only choice she can towards self-preservation, and marries Collins.  She makes the best of her situation and lives a comfortablee if not loving and joyful life.

The fact that Elizabeth is in a similarly dire situation but refuses Collins's proposal and states, emphatically, that she will only marry for love also emphasizes the satire.  As the hero of the story, Austen makes it clear that this is the better attitude to have and this is the ideal that women should be allowed to live to.  Elizabeth's strength in refusing not one but two unacceptable proposals is to be applauded, and we can then doubly enjoy the wonderful, romantic happy ending where Elizabeth gets it all -- the wealth, and more importantly, the love.

Humor is a way of presenting things that are amusing. One way to make something humorous is to present something that is absurd, illogical, or lacks common sense. Jane Austen uses many absurd characters to present humor. One is Mrs. Bennet, who is always going on about her goals to get her daughters married, who acts contrary to social requirements, and is always going on about her nerves. Another is Mr. Collins who has no mind of his own, always accepts Lady Catherine's commands, and yet feels very proud about his position as clergyman. A third is Lady Catherine herself, who is rude, condescending, and who traveled all the way to Longbourn to command Elizabeth not to marry Darcy, even though Lady Catherine herself claimed that such a union would be an impossibility.

Another way to present humor is through wit. We see a great deal of wit in Elizabeth who is very quick to point out the amusement and irony of a situation. For instance, when Lady Catherine demands to know if she is engaged to Darcy, Elizabeth quickly points out that Lady Catherine has already "declared it to be impossible" (Ch. 14, Vol. 3).

A final way in which we see Jane Austen employ humor is through irony. Austen uses many different types of irony, including situational irony, in which there are turns in the plot, and dramatic irony, in which the character's words come back to haunt them. Irony can be amusing because it is intelligent and witty.

Satire is a source of much of the book's humor. It is used, for instance, to highlight the ridiculousness and hypocrisy of the genteel marriage market in Regency England. And in the absurd figure of Mrs. Bennet, we have a symbol of the warped social values that such a view of marriage entails. Yet Mrs. Bennet is no mere caricature; otherwise, Jane Austen's gentle satire on society's mores would be considerably less acute. There has to be a ring of truth about Mrs. Bennet to make her an effective character.

So Austen uses the calm, wise and mordantly witty Mr. Bennet as a foil to his ludicrous, over-emotional wife. Where Mrs. Bennet gets all flustered over Lydia's elopement, Mr. Bennet calmly goes about the practical business of tracking her down. And when Mrs. Bennet is anxious that Mr. Bingley's ardour towards Lizzie appears to have cooled somewhat, Mr. Bennet takes a more relaxed view of the situation, finding in it a source of amusement:

"So, Lizzy,'' said he one day, "your sister is crossed in love I find. I congratulate her. Next to being married, a girl likes to be crossed in love a little now and then. It is something to think of, and gives her a sort of distinction among her companions. When is your turn to come? You will hardly bear to be long outdone by Jane. Now is your time. Here are officers enough at Meryton to disappoint all the young ladies in the country. Let Wickham be your man. He is a pleasant fellow, and would jilt you creditably."

The satirical thrust of Pride and Prejudice also finds generous expression in the figure of the oily and ingratiating Mr. Collins, a man constantly harping on about the value of social rank, yet owing his position in life to nothing more than shameless flattery and social climbing. Indeed, Austen describes him as

not a sensible man, and the deficiency of nature had been but little assisted by education or society.

It says something about provincial society in Regency England that a man like Mr. Collins can attain such a respected position.

Social snobbery is such an obsession with Mr. Collins that distinctions of rank aren't simply a matter of life and death; they're so much more important than that. In such a society, reputation is all, especially for young ladies, as Mr. Collins clumsily expresses to Mr. Bennet:

The death of your daughter would have been a blessing in comparison of this.

Yet ironically, Austen's portrayal of Mr. Collins is not so much a satire on snobbery as an expression of it. Austen is no less committed to the existence of a hierarchical society here as elsewhere in her work. (Such as Emma, for example). What she objects to is people not knowing their place in society; of getting ideas above their station. Mr. Collins presents such an absurd, ridiculous figure precisely because of his shameless social climbing and obsequious regard for Lady Catherine De Bourgh.

One example of humor Jane Austen uses in Pride and Prejudice to expose the ridiculousness of the search for marriage can be seen in the opening scene. In this scene Mrs. Bennet is trying to persuade Mr. Bennet to visit and introduce the family to Mr. Bingley who has just purchased the Netherfield estate. The conversation is particularly amusing because Mr. Bennet teases his wife about her interest in Bingley for their daughters. In particular, Mr. Bennet asks how Bingley's taking Netherfield could affect the girls and when Mrs. Bennet asserts that Bingley might fall in love with one of them, Mr. Bennet replies that he sees no reason to visit Bingley, but Mrs. Bennet and the girls can go, which of course, would be a social faux pas.

A second example is seen when Mrs. Bennet learns that Wickham has successfully been forced into marrying Lydia. Rightfully, when Mrs. Bennet first learns that Lydia has run off with Wickham, she bemoans the fate of Lydia's reputation and the rest of her family's reputation.  However, when she learns Lydia will be married, all thoughts of Lydia's wrong-doing fly right out the window. Instead, Mrs. Bennet is jubilant that she finally has one daughter married and demands Jane and Elizabeth to ask Mr. Bennet how much money he will give Lydia for the wedding clothes. The humor in that scene is the irony in her sudden change of behavior when the circumstances haven't changed at all.

Jane Austen uses wit to emphasize social norms. Like many other satirists,  she holds to a strict sense of what are appropriate forms of social and interpersonal intercourse, and uses ridicule to indicate disapproval or unmask hypocrisy. Wit and humour are expressed verbally in the voices of the narrator and Elizabeth Bennett and often situationally or unintentionally as other characters unmask their own foibles with inappropriate actions or words.

Technically, Austen often uses indirect discourse to create humour. He omniscient narrator looks at what Elizabeth is thinking, and expresses what Elizabeth is too polite to say -- the humour often is created by the contrasted between what is thought and what is said, e.g.  To Elizabeth it appeared that, had her family made an agreement to expose themselves as much as they could during the evening, it would have been impossible for them to play their parts with more spirit or finer success…”

Mr. Collins is another major source of humour in the novel, in that his pompous pronouncements are often in conflict not only with everyday reality but also with common sense. His praise of and obsequiousness towards Lady Catherine de Bourgh is both funny, that she is unpraiseworthy, but also the contrast reveals the serious social issue of her wielding vast power gained simply by being born to the right parents rather than by instrisic merit; what makes Jane Austen's wit worth re-reading and why it has endured is that it expresses graceful indignation at injustice.

It is generally known that Jane Austen uses humor in a subtle (yet effective) way in her writings.  Humor is infused into the story through the actions of specific characters whose traits are quite salient from the rest. These characters are often obnoxious (Mr. Collins, Mrs. Bennet, Mary), “full of themselves” (Miss Bingley, Mrs. Hurst, Darcy, Lady Catherine, and Mr. Collins), or foolish (Lydia, Charlotte, Sir Lucas).

These secondary characters’ traits often clash with the main character, creating with their actions a remarkable contrast that results in humor. A good example of this would be the visit of Mr. Collins to the Bennet household.  After the reader witnesses his mannerisms and his fixation with Lady Catherine De Bourgh, his aristocratic patroness, it is evident that Mr. Collins and the main character, Elizabeth, are complete opposites. When he then proposes marriage to Elizabeth, the weirdness of it all creates a very funny situation in which both characters end up in a very awkward conversation. The result was that Elizabeth rejected Collins, and his ego was hurt tremendously.

Therefore, Jane Austen does not openly break from the flow of the narrative to create a funny situation. Instead, she presents specific characters whose behaviors are curious, interesting, and funny. It is through their actions that humor occurs in the story.

Pride and Prejudice was not well-received in some circles when it was first published as Jane Austen did not meet the standard of 'literature'

as an idealized higher reality.

Whilst her novel was considered to be entertaining and witty, the realism of the inept characters she portrayed reduced the novel's effect as literature is supposed to be uplifting not purely entertaining.  

The sarcasm in Pride and Prejudice is evident from the beginning, the opening line comments 

It is a truth universally acknowledged that a single man in possession of a good fortune must be in want of a wife.

Irony is widely used and Reuben A Brower commented

The triumph of the novel—whatever its limitations may be—lies in combining such poetry of wit,...with the dramatic structure of fiction.

He even compared her to Alexander Pope

without couplets...

The characters, especially Lizzy and her father are good examples of the use of irony and satire. Lizzy, with her 

lively, playful disposition, which delights in anything ridiculous,

and Mr. Bennet concluding that one of the purposes of life is to provide 

sport for our neighbors, and laugh at them in our turn

Mr. Bennet intends to invite Collins to visit and hopes that his absurdity will be entertainiing.

Lizzy subtly taunts Lady Catherine by flouting her expectation of deference.

Further use of Irony is apparent when Lizzy, refusing to dance with Darcy, tells Sir William that

Mr. Darcy is all politeness,

Mr. Bennet says (as a joke),

I admire all my three sons-in-law,...Wickham perhaps is my favorite.

Jane Austen used irony purposefully in  Pride and Prejudice, a novel so wrapped up in the ironies of the day and the need to marry well, thereby resolving the main issues surrounding the marriage plot andbecause it is able to acknowledge

a multiplicity of perspectives simultaneously.

The eNotes study guide will help you understand the styles used and navigate to the 'Essays and criticism' section where you will find references to the humor, amongst other helpful information.  

Certain characters like Mr. Collins, Caroline Bingley, and Mrs. Bennet help to make the novel comical.  Mr. Collins is a prize idiot, something that everyone but Mrs. Bennet and Mary seem to realize.  He has stupid opinions about marriage and women's reading and propriety and how to treat women, and he fails to realize just how ridiculous he is.  Then, Miss Bingley tries again and again to lower Elizabeth in the eyes of Mr. Darcy, failing repeatedly.  Her machinations to tempt him into love with her are so transparent and obvious that they end up being funny.  Mrs. Bennet is another such character: her constant complaining about her "nerves," her desperation to marry her daughters off to whomever she can, and her husband's complete inability to be in the same room with her for more than five minutes together make her comical too.

Further, scenes like the one at the Netherfield ball, when Elizabeth is almost convinced that her family has conspired to make themselves ridiculous all at once are quite comical as well.  Her mother is talking loudly about a wedding between Jane and Mr. Bingley (when he's not proposed yet), Mary is hogging the attention of the party by singing, badly, Mr. Collins embarrasses himself first in front of Mr. Darcy and then, again, in front of the entire party when he waxes philosophic about music, and even her father publicly redresses Mary, interrupting her mid-song.  As the reader can most likely relate to poor Elizabeth's feelings, her mortification both makes her more appealing to us and more sympathetic as well, but we cannot help but chuckle at how perfectly timed everyone's bad behavior is. 

Pride and Prejudice does offer a myriad of humorous characters, situations, and outcomes that are a reflection of Jane Austen's own views of society. The character of Mr. Collins for example, is worthy of humor. His obsession with Lady Catherine de Bourgh and Lady Catherine's own high importance and exaggerated mannerisms have traces of mockery blended in with passive sarcasm. The relationship between Jane and Bingley is humorous as well because both are really very plain and weak. If one sees how their love affair develops, a lot of blanks spaces will remain open. How in the world did they even fall in love? Why so into each other? How tacky they are!

Elizabeth's teasing of Darcy could be considered humorous because he mainly remained quiet taking it all in. The Lucases are tacky and corny with Sir Lucas's title and his references to the St. James's.

Even imagining the actions of Lydia, Mary, Elizabeth's father, Mrs. Bennet, and Kitty during the ball at Bingleys and how it embarrassed the world out of Elizabeth and Jane is also a clear criticism towards country folk versus the fashionable city folk.

For these reasons, Pride and Prejudice can be a drama and a comedy at any moment. Depending on how we read it.

You can hardly read Pride and Prejudice and ignore the narrator's delight in making ironic, witty comments about her chararcters. Frequently these come through the mouthpiece of Lizzy Bennet, but they also are common occurences from the omniscient narrator. To give just one example, Lizzy Bennet employs a rather cruel form of irony to describe Miss De Bourgh on her first meeting:

"I like her appearance. She looks sickly and cross. Yes, she will do very well for him."

In this example of irony we need to possess knowledge about matters exterior to the context in order to detect and fully appreciate the irony. Here, obviously Lizzy does not like the appearance of Miss De Bourgh - her "liking" is only based on her dislike of Mr Darcy and his and Miss De Bourgh's intended union. Such use of verbal irony, or saying the opposite of what is really meant, is used throughout this novel, but the reader must be aware of the wider context in order to detect and enjoy the uses of irony.

Irony definitely extends beyond the verbal in this novel however. It is highly ironic that Mr. Darcy, having just persuaded Mr. Bingley to abandon his pursuit of Jane Bennet, then goes on to propose to Lizzie Bennet, in spite of exactly all of the same objections standing against such a union. Likewise, Lady Catherine's visit to Lizzie Bennet to try and prevent the union of Darcy and Elizabeth, unknowingly and highly ironically, is a key event that brings her nephew and Lizzie Bennet together.

That is enough to get you started - you might also want to think about the kind of irony employed by various characters, and indeed, the narrator herself. Linked to this you will want to examine the characters irony is used against and their awareness - or not - of the irony that is employed against them.

Irony, the contrast between the actual reality of something and the appearance or expectation of something, is one of the main stylistic components of Pride and Prejudice.
The very first statement of the novel, “It is a truth universally acknowledged, that a single man in possession of a good fortune must be in want of a wife,” sets the tone for a work of irony. In reality, it is mostly the women in the book who are chasing after men in order to secure a fortune. As the title suggests, the novel explores how people’s pride and prejudices get in the way of their feelings and actions. Elizabeth and Darcy begin the novel hating one another. Each thinks the other is stuck up and not worthy of their attention. And yet, they overcome these prejudices and much hurt pride and come to love one another. Austen uses irony in her works in order to expose the true nature of her characters and allow them to realize their prejudices, overcome their pride, and grow as people.

The comedy and satire in Pride and Prejudice both center around the search of the young female characters, in particular the Bennet sisters, for a husband. The famous first sentence alerts the reader to this, with the ironic twist that the "want" is ascribed to the single man in possession of a good fortune, rather than to his prospective wife or, even more accurately, her mother.

With the possible exception of Lady Catherine de Bourgh, who is a caricature of patrician haughtiness and entitlement, Mrs. Bennet is the most purely comic of the female characters in the novel. Her one fixed idea is that she must get her daughters well married, and all her principles and preferences serve this single thought. She hates Mr. Collins until he shows an interest in marrying one of her daughters; then she loves him, and her attitude to Mr. Darcy is just the same.

The comedy in the presentation of Mrs. Bennet and her daughters, however, is somewhat at odds with the satire. Mrs. Bennet is a ludicrous figure and a foolish woman, but according to the standards of her society, she is a good mother, while the kindly, cultured, intelligent Mr. Bennet is a bad father. In the society Austen describes, to remain unmarried is a terrible fate for a lady, particularly if she has no money of her own. Charlotte Lucas will gladly sacrifice herself to the odious Mr. Collins rather than face such a prospect. The consternation caused by Elizabeth's refusal to make a disagreeable match (and by Lydia's making an unsuitable one) shows that the true target of Austen's satire is not Mrs. Bennet's folly but the cruel absurdity of a society in which the destinies of women are so entirely dependent on marriage.