Communication is a central theme in this play, shown through the miscommunication between Hero and Claudio. Claudio is tricked by Don John into thinking Hero is unfaithful. Don John shows Claudio an encounter between Borachio and Margaret, claiming Margaret is Hero. Claudio chooses to disgrace Hero at the altar, choosing to believe his eyes over her words. He does not listen to her protests. It is not until Borachio confesses his part in the deception that Claudio believes in Hero's innocence. We should also note that Borachio's confession comes from his guilt over hearing of Hero's death. However, Hero is not actually dead, so this is another deception in the play. Hero is presented to Claudio in the final scene masked, and when she lifts her disguise thus ends the final deception in the play.

Shakespeare plays with language in this play. Beatrice and Benedick often engage in a battle of wits, using language in their jests. Although they are two of the most famous examples of characters with strong language skills, they are not the only ones present in this play:

Margaret, fancying herself as good a wit as Beatrice, gets in a pointed stab when she advises Beatrice, "Get you some of this distilled carduus benedictus and lay it to your heart. It is the only thing for a qualm." And Hero quips, "There thou prick'st her with a thistle." The pun and double entendre is obvious.(Enotes.com Act III, Scene 4 Summary and Analysis)

Dogberry is known for his malapropisms, or incorrect use of words:

"One word, sir. Our watch, sir, have indeed comprehended two aspicious persons, and we would have them this morning examined before your worship."

He means to say "apprehended" and "suspicious," and his misuse of the words add to the comedy of the play.

Language and communication are central themes in Much Ado About Nothing because the drama in the play is created and sustained by language. From misunderstandings to manipulations to saucy fights between would-be lovers, Much Ado About Nothing uses language to place people against each other and bring them back together.

If people were straightforward and said what they thought, the play wouldn't progress as it does. The ability of language to mislead and cover up true feelings is essential to the story. People mishear each other, impersonate each other, and generally play with language to achieve their own ends.

One example of the importance of language and communication is the character of Don John. He spends the entire story manipulating those around him by using words to convince them that he has their best interests at heart. Lying is an art for Don John; he drives most of the negative action of the play by twisting words around.

Borachio and Margaret pretending to be Borachio and Hero is another example of the importance of language and communication. Because they speak as if they are lovers, Hero's virtue is suspect. It doesn't matter that Margaret is merely pretending to be Hero; her words still cast doubt on Hero's character because people can't see who is truly communicating.

Later, Borachio brags about what he's done. This free-flowing and inappropriate communication is what ultimately undoes the plan. Constable Dogberry overhears his words and uses them to prove Hero's innocence.

Shakespeare's Much Ado About Nothing is fraught with attention to language, word play, and the act of communicating (or not communicating!). The title itself is a lighthearted play on words: "nothing" refers to "noting," a word which once meant "to gossip."

It is through the power of language and communication that the story's protagonists, Benedick and Beatrice, come together; language is also what makes this reunion so comical and sweet due to the pair's obsessive, loud insistence that they despise each other.

The first remarkable instance of the use of language occurs in Act One, Scene One, when Benedick and Beatrice engage in an epic battle of tongues: they fight each other verbally with each retort riffing off the language that the previous lash used. For example, when Benedick attacks Beatrice, saying, "Well, you are a rare parrot-teacher," Beatrice spits back, "A bird of my tongue is better than a beast of yours," to which Benedick speedily replies, "I would my horse had the speed of your tongue, and so good a continuer." See how Beatrice carried on the metaphor involving birds to her comment, at which point Benedick picked up on the tongue from hers? These two are all wits and wiles in an argument, and their mental agility is thrilling to read or watch. 

The next major instance involving language occurs in Act Two at the masquerade ball, where Don Pedro (the Prince of Aragon) agrees to help a very nervous Claudio (a friend of Benedick) court beautiful young Hero (cousin of Beatrice). Another deception occurs here as well: in disguise, Benedick convinces Beatrice to dance with him. This masking of words and of intentions leads to the next instance...

Don Pedro and friends decide that they will prank Benedick, and Hero and her maid decide to deceive Beatrice. Beatrice is set up to overhear the women talk about Benedick's love for Beatrice, while Benedick is set up to hear the men talk about Beatrice's love for Benedick. It is through this act of mis-communication that the two rivals find unlikely love with each other.

These patterns of gossip and of manipulating words to benefit the speaker or others continue throughout the rest of the play with varying effects. Don John, the evil "bastard" brother of Don Pedro maliciously uses language to destroy Hero and Claudio's wedding by lying to Claudio about Hero's "unfaithfulness." Claudio then uses cruel language to humiliate Hero at their ceremony. Dogberry, the master of the Watch and a frequent user of malapropisms (incorrect word usage due to similarities in sounds or pronunciations), ultimately saves the day by forcing a confession from the antagonists behind the wedding fiasco. Of course, the play ends with another intentional miscommunication: Hero's family pretends that she is dead and convinces Claudio to marry her "copy." As all comedies do, this ends well for the couple: Claudio is able to marry the woman he once defamed, her reputation is restored, and Beatrice and Benedick are united as well.