how do I understand if they like me?

Q - I can pick-up women quite easily. The problem is that I don't know how to proceed from there and I can't understand if they like my presence or if they listen to me only because they have nothing better to do.

A - I understand your problem. Talking with someone that would like to be somewhere else is an extremely unpleasant experience. If you want to understand if your interlocutor is effectively interested to the conversation and, consequently, to you, do not listen to what she says with her words but with her body. Does she lean forward pretending she cannot hear what you are saying? Does she touch or caress objects nearby like a glass or a ring? Does she assume a posture identical to yours, maybe crossing the same leg?

In all these cases she is quite surely interested to what you are saying. On the contrary, if, for example, she looks somewhere else, if she looks at her nails or if her body is completely relaxed and is
pulling back from yours resting on the chair, then it would be better for you to change the topic of your conversation or to change person altogether. I would choose the second option, because a person that is
really interested in you will attentively listen to what you say even though you are enunciating a nuclear physics theorem.