Trust men's words and compliments. Pay attention to how unbanal you are praising the man. If he notices you what that stuff, then you definitely interest him. But if nothing but praise your beautiful eyes you can't hear, but it should be wary. It is likely that he speaks the same words to all women, with whom it has relationships. Truly a man in love will always notice in his beloved something special.
Believe the actions. Note how the man behaves with you. If he's in love, you will notice that he cares about you and is trying in any place to create a comfortable environment. Do not dismiss such apparently small things as the fact that he never held the door open, not held out a hand. It says more about negligence to your person. Don't try to justify male bad parenting. Even the last rogue becomes a true man in the society of the woman he is in love.
Please note, if he lets you in his life. If a man is really serious about you, he will surely introduce you to their friends and family. A rare man will not fail to boast of his girlfriend in front of friends. Also think about how much do you know about him. A man in love will try to tell you about my life. Because only the woman can trust to the end.
Still, don't treat a man too suspicious. Listen to your intuition. Maybe for doubt, and does no reason. If you feel a sincere love, do not spoil relations with unnecessary distrust.