Men often send mixed signals regarding their romantic intentions. It's up to the woman to discern whether the man is genuinely attracted to her or simply seeking to fill his stable full of women he can have on his speed dial. No woman wants to be dating a man for the purpose of feeding his ego, so women have to use their intuition and powers of observation to determine if the man she likes is actually attracted to her, or simply playing around.
Watch who he pays attention to when you are in public. Does he give most of his attention to you, or does he seem to take it for granted that you'll be there waiting when he's ready to stop talking to the girl in the pigtails and miniskirt? He doesn't have to spend every moment talking to you to show attraction---he'll naturally want to talk to his friends---but if you are the last person to grab his attention when you're around other people, chances are he's not very attracted to you.
Observe his reaction to your appearance. Is he complimentary, or does he make suggestions on ways that you could improve? Some men do not express their attraction verbally, but if he thinks you look good, he may smile, raise his eyebrows and even whistle under his breath. If he is at all critical, he is probably not attracted to you. Men who are really attracted to a woman tend to think she would look OK wearing a feed sack.
Note his appearance. When he knows he will be seeing you, how does he dress? Does he put his best fashion foot forward, or is he wearing three day growth on his face and the same t-shirt he wore yesterday? When a man is attracted to a woman, he will often make an extra effort with his appearance. The same applies to behaviour. A man who might otherwise curse and belch over a few beers is likely to curb those behaviours around a woman he is attracted to, at least temporarily. Does his appearance and behaviour reflect that of a man who is interested in making a positive impression?
Study his body language. When you are talking to him, does he cross his arms or maintain an open, friendly body posture? What about eye contact? Does he look you in the eye directly, or does he tend to glance away frequently? Looking away can indicate discomfort, which can be caused by a lack of attraction, or perhaps shyness. Does he let you in his personal space, or does he keep his distance?
Look at the size of his pupils when he is talking to you. When someone is attracted to another person, pupil size tends to increase. Smiling can also be a sign of attraction. Notice if he smiles more around you than most other people.
If you decide that the man you like is attracted to you, the battle is not yet won. Dating expert Evan Marc Katz points out that it is easy for guys to be attracted to women, but not so easy to be attracted to a woman and also find her interesting. So once you are certain of his attraction, make sure you can hold his interest.