How do you know if a guy is in to you at all when there's around people he ignores me when I'm just with him he talks to me?

Answer 1

There are two likely possibilities:

1. He does like you, but does not believe his friends or social group will approve, and thus keeps your friendship sort of "secret".
2. He is only using you as a friend when he has nobody better.

Either way, you need to force his hand. If you like him, ask him directly "do you like me too?" with no preamble hinting of your feelings; he should notice the emphasis on "too" and understand you like him, but want to be sure it is a mutual thing before going further. His reaction should tell you what you need to know: if he is defensive, then he doesn't, if he is confused or cautious, then he thinks maybe, if he acts positively, then he probably does.

If you don't like him, just ask why he treats you differently when in groups and when alone. If he is a good enough friend to really care about you, he will see the error of his ways and possibly apologise or try to talk about the problem. if he is just using you as a substitute, then he will basically skip the subject and try to change the conversation away from it.

In any event, after one of the above options (or your own plan) start to react when he is different; when he ignores you, leave; when he talks to you alone, make sure he pays attention etc. If he does care, these will be further hints of it, and with some decent observation you should be able to tell what he thinks about you in general - i.e. whether you are a second-choice, a good friend or maybe more than that.