Let me take a stab at this from a guys perspective.
From ages 6 to 12
He will treat you like one of his guy friends. You may get punched, but not too hard. You will be the center of attention but not always in a way you may like. He secretly may share his lunch with you but not when the rest of the guys are watching. He cannot really be seen "noticing" a girl. His attentions may sometimes seem mean but it is a self preservation tactic on his part.
From age 12 to 18
This is sometimes the worst period for guys and the girls they like. He still wants to be in with the "guys" but he is torn between that and oh so wanting to catch your eye. He is clumsy, both physically and with words that come out all wrong. He can often ignore you but you will catch him looking at you with a slight smile. His priorities are still with the "boys" because some catch on sooner than others. The more you let him know you are interested the braver he will be. A big worry at this age is rejection. He has no idea what he is doing but he cannot help himself. He will need encouragement and guidance.
From age 18 to 30
Mr. Self Confidence. He has it all under control, or so he thinks. He still maintains the "one of the guys" attitude but often shows some promise in the romance and thoughtfulness category. This will be infuriating to you at times. At this age, you will be able to sort the wheat from the chafe.
From 30 to 50
Mr. Comfortable. You will often feel taken for granted. You will feel a need for more and he will like the status Quo. Some get into a routine that is unshakable. Others will look for changes.
From 50 onward
Priorities change somewhere around this age. Home, family and the need to be settled. You should be the very heart of his world by now. For most, the need to be "one of the guys" is put aside. Enjoy this, it should be the best of the years you have left together.
iam in love with this guy but i do not know if he likes me or some other girl
when he says he likes you.
If a guy likes you but you don't know him he may look at you or walk by you whenever possible.
http://www.wikihow.com/Know-if-a-Guy-Likes-You
Not sure how you expect someone to magically know something.
It is ok to like a guy after you know he likes you. That is perfectly normal and a part of life.
You ask the guy.
don't
When he has a penis.
his eyes will open wider if he likes it
You will know if a guy likes you because he will ask you alot of questions and he will try to get to know you better,but don't think that just because he talks to you that he likes you,make sure that they are the right person!!!
what I do is just kind of talk about what he likes or just be funny because a guy likes a sense of humor.