Let me give you a really simple clue: He is around you.
More than 98% of the time, if a guy likes you, then he is going to be around you.
He will start talking to you or he will just stare at you.
It doesn't really matter if he is not talking directly to you or even blatantly ignoring you...
Maybe he will smile at you, maybe not, especially if he is a shy guy.
Sometimes he will even make fun of you.
One way or another, no matter what he is doing, he is doing it around you.
However, you should know that this doesn't mean that the man you are interested in is going to be right next to you.
But logically, if he IS interested in you, he will find reasons to be close to you.
And sometimes that closeness means he will look at you from across the room.
"But he never says anything to me!" - yes, that can be a huge problem with shy guys.
But, just because he is shy, that doesn't mean he is not interested in you, all you need is different approach.
Try to understand that most men, no matter how old they get, never grow out of this.
That is in their nature.
Looking from another angle, no matter what a guy is doing, if he is not doing it around you, logically he has no interest in you.
If he is not around you that much, then he probably doesn't have any feelings for you.
You see, just as they have trouble telling someone that they DO like them, they have the same trouble telling someone they don't.
So, they solve that by avoiding that person.
Sorry, but that is they way.
Anyway, the final answer to the "how to tell if a guy likes you" question is: the best sign to look for to see if he is interested in you is if, no matter what he is doing, he is doing it around YOU.
So now, you are ready to catch that guy and keep him.
All the best, Mike