Understanding whether a guy is interested in you or not is not as difficult as it may originally seem. You have to look for specific signs to be absolutely sure and to avoid misunderstandings that can make both you and the guy feel uncomfortable. The following article might help you in that direction.
How to tell if a guy is interested in you
He wants to see you all the time
Whether the guy is a friend of a friend or someone you met on your own, if you notice that he looks for excuses to see you all the time then he is definitely interested in you in a romantic way. If you still have doubts, what you can do is ask him if it will be okay with him to bring a friend with you. If he seems uncomfortable with the idea and he tries to convince you that only the two of you should go out together, then you can rest assured that the guy is interested in you, especially if that happens every time you make such a suggestion.
He goes out of his way to please you
If a guy goes out of his way to please you all the time by being willing to take you to places he doesn't like but you like, by refusing to talk about topics that are too sensitive for you to deal with and by backing off to avoid confrontation with you then he probably is romantically interested in you and he does not simply try to be a gentleman.
He is jealous of other guys
If a guy is jealous of any other guy in your life, this is another sign that he is romantically interested in you. If he keeps asking you all kinds of questions about them and the kind of relationship you have with them, then rest assured that his interest in you is definitely not just friendly. He is not just trying to be protective of you, he is also trying to ensure that you will not get involved romantically with any of them. In a case like this, if the guy senses that something is about to happen between you and any of these guys, he might be forced to express his real feelings for you.
If you observe the above signs or at least, most of them, then you can be sure that the guy is interested in you.