How does Romeo find out that Juliet shares his love?

For the audience, there is not really much question as to whether Juliet is in love with Romeo. The start of act 2 has the Chorus announce to the audience members that Juliet is madly in love with Romeo.

And she as much in love, her means much less
To meet her new beloved anywhere.

Romeo must wait until act 2, scene 2, before he hears Juliet confess her love. This is the famous balcony scene, and Romeo overhears Juliet talking about her feelings. However, Romeo really wants her to say the words to him.


I take thee at thy word.
Call me but love, and I’ll be new baptized.
Henceforth I never will be Romeo.



Juliet does not immediately say the word "love" to Romeo. Instead, we get a lot of flowery love talk between the two of them. She gets close to saying the words that Romeo is hoping to hear when she says, "This bud of love." She is admitting that there is love, but she has not expressly said that Romeo is the object of her desire.


Sweet, good night.
This bud of love, by summer’s ripening breath,
May prove a beauteous flower when next we meet.


Eventually, Juliet does get around to telling Romeo that she loves him, and she tells him that her love is deep and boundless.


My bounty is as boundless as the sea,
My love as deep. The more I give to thee,
The more I have, for both are infinite.

Romeo hears Juliet confessing her feelings when he is standing in her garden and she's speaking to herself on her balcony.
After Romeo sneaks into the Capulets' ball and sees Juliet, he finds himself instantly in love with her. As the Chorus details in the prologue of act 2, he's set aside his love for Rosalind in favor of Juliet. He doesn't want to be parted from her. Once he's under her balcony, he sees her approach and listens to her speech.
Juliet wonders out loud why Romeo has to be a Montague, the sworn enemy of her family. She says that she wishes he could forsake his family and that she'd forsake hers for him if he declared his love. Juliet says that she wants him to forsake his name to be with her.
Romeo—whose presence was unknown until this point—answers and offers to do so.