Because of her social position and historical context, Juliet is representative of a girl who has no real voice in many decisions which govern her life. Her marriage to Paris is arranged with her father and without any of her own input. In act 1, scene 2, we learn that Paris has requested to marry Juliet that and Lord Capulet has some hesitations. Juliet "hath not seen the change of fourteen years" (I.ii.9), and Lord Capulet believes that marriage might force Juliet to grow up too quickly. But because Paris represents a good match for the Capulet family, he eventually persuades Juliet's father to agree to the marriage.
Meanwhile, Juliet falls in love with Romeo. She has no plans to marry Paris and is fairly shocked when the wedding date is set with only three days of notice.
In act 3, scene 5, all of this comes to a climax when Lord Capulet demands that Juliet do as commanded and marry Paris. Juliet begs to avoid this hasty marriage, noting that Paris has not even come "to woo" her.
Lord Capulet explodes. Juliet has crossed several lines in her refusal to marry Paris. First, as a woman, she is expected to submit to the desires of male leadership. Second, as a daughter, she is expected to submit to her father.
Juliet's attempts to forge her own path in life and to make her own choice in marriage meets a harsh response from her father, who tells her,
Thursday is near. Lay hand on heart, advise.
An you be mine, I’ll give you to my friend.
An you be not, hang, beg, starve, die in the streets,
For, by my soul, I’ll ne’er acknowledge thee. (III.v.201-204)
Though Juliet fakes her own death to avoid the marriage to Paris, her father fully intends to force her into the marriage against her wishes—because her wishes mean nothing to him in their patriarchal society.
When Paris first approaches Juliet's father about marrying Juliet, Capulet is reluctant. She is his only remaining child - the rest have died. Paris points out that many girls Juliet's age are already married. Capulet agrees, but is still reluctant and encourages Paris to woo Juliet. Lady Capulet is excited by the prospect of the marriage and eagerly brings the news to Juliet.
Juliet meets Romeo, falls in love and marries him. After Romeo is banished, Juliet's tears are believed to be in response to the death of her cousin Tybalt. Capulet decides that Juliet needs to marry Paris. When she refuses her father, he becomes irate and threatens that he will disown her - and throw her out of the house - if she does not obey him. Juliet appeals to her mother. Lady Capulet tells her that she will have nothing more to do with Juliet if she does not obey her father.
Juliet's parents don't understand Juliet's reluctance to marry Paris - after all, he's a great match.
Juliet's parents attempt at forcing Juliet to marry Paris. Her father, Lord Capulet, says to her in Act III, scene v, lines 197-198, "But, an you will not wed, I'll pardon you./ Graze where you will, you shall not house with me." Lord Capulet is basically stating that should Juliet refuse marriage to Paris, he will "excuse" her to find another home and for her to go where she wants because she won't live in his home.
Lord Capulet also states in the same scene, lines 202-204, the following: "An you be not, hang, beg, starve, die in the streets,/ For by my soul, i'll ne'er acknowledge thee,/ Nor what is mine shall never do thee good." In other words, if Juliet does not marry Paris, he will no longer claim her as his daughter and would let her die in the streets.
When Juliet pleas with her mother, the reply from lines 212-213 are "Talk not to me, for I"ll not speak a word./ Do as thou wilt, for I have done with thee." Lady Capulet refuses to come to the aid of Juliet and therefore by inaction sides with her husband.
Overall, while Juliet is not physically forced to marry Paris, her parents use all means to unkindly persuade her to make the choice by stripping her of her name, home, and family if she were to choose not to.
When Paris first says he wants to marry Juliet, Lord Capulet (her father) specifically says "woo her" and indicates that his permission is only part of the deal and that Juliet has to agree too.
Later, Paris asks again and Lord Capulet says Juliet should listen to his suggestion and marry Paris. That's in between.
Eventually, though, it does come to force: Lord Capulet says he will drag her to the church to get married.
They are planning on making Juliet marry Paris, because they do not know about Romeo (not that they would have approved of the match even if they did.) They cannot, however, because Juliet fakes her death, and then actually dies, before they would marry.