Hi Zaira ~ welcome to the forum.
I think that it's usually possible to tell if someone likes you by their behaviour ~ if they are kind, considerate and friendly.
They do say that there are clues in body language, etc, like if they sit or stand quite close, but without making you feel uncomfortable, or if they make eye contact a lot or brush past you. There are books, and probably websites, on the subject.
There is, apparently, a way of telling if someone loves you ~ when they look into your eyes, their pupils dilate!