"O Romeo, O Romeo, wherefore art thou Romeo? Deny thy father and refuse thy name." In these sentences, imperatives are used. What do these verbs tell us about Juliet’s idea about love?

Juliet believes she is alone on her balcony here, so this expression speaks to her passion and impetuousness. That morning, she was a young girl completely unconcerned about adult emotions. Her mother asked her to try to fall in love with Paris but instead she finds Romeo. She has had little time to reflect on love or to contemplate how she will feel once she enters a relationship.
The suddenness of her adult passion and erotic desire has overwhelmed her, and the imperatives show this. She has embraced fully into this new experience. "Deny" and "refuse" speak to her absolute commitment to love.
Juliet's willingness to place romantic love above every other commitment defines the nature of her tragedy. She is able to make up her mind very quickly about what she wants and to pursue it without hesitation. Moments after this exclamation, talking with Romeo, she decides that since he overheard her, there is not point playing games with love. She then arranges for their marriage.

Juliet says this in act 2, scene 2, when Romeo overhears her as she speaks on her balcony. Using imperatives, otherwise known as commands, she tells Romeo (who she thinks is absent) to forget about his father and to change his name. In doing so, Juliet assumes control over Romeo's future. She asks him to leave his family and reject his entire heritage.
By speaking this way and using imperative verbs, Juliet signifies that she is demanding and willing to embrace radical measures in order to be with Romeo. Later in the same speech, she says that even if Romeo will not change his name, she will change hers if he just promises to love her. Juliet's ideas of love are all-consuming and black and white. She assumes that Romeo cannot love her if he is still connected to his family or she to hers. She is willing to embrace extreme measures to be with her love.