I like a girl. I sent her a message expressing my love, but she didn't reply. What should I do?

First of all, there is a possibility that he didn't reply to your message because he happened to be busy. In that case, you can wait for him for a few more days.

Second, it may be because he received your message, but he doesn't like you, but he doesn't know how to refuse you, so he can only turn a deaf ear to it. If so, you can ask her face to face what she thinks of you. If she makes it clear that she doesn't like you, then you should take the initiative to let go or stay with him, touch her and make her like you.

Third, it may be because when you like the other person, the other person likes you very much, but it is also because he likes you, so he is nervous and at a loss, and wants to reply to your message, but in order to leave a good impression on you, he is trying to think about the wording.