If you're talking about when it comes to an argument. I think most people find the time to sit down with the other and think about what he or she has said about something. You might want to take into consideration that not ALL men are big jerks that want people for sexual relations. Anyway, you'll know the guy is right when the time comes that whatever the argument was about and he says this and this will happen and it comes true - you'll know he's right.
when he does not treat you right
You just know.
he respects you
Once you start dating, and the guy seems really interested and nice and funny to you, then you'll know ;)
When you are married and in you are both in your 50's.
If you know the right guy.
you need to know that he likes you too and wants to tell you that.
Then you should ask him out. Or be his friend and talk to him for a while and after that ask him out. Its that simple!
Of course. Any guy you actaully love is going to be the right guy. You can't always choose who you fall in love with though. It just sorta happens.
if they treat you right and give you respect
If you like a guy than wait for the right moment then you"ll know when to kiss him but dont go to far "if you know what im saying".
or he dont clean up his mess. or he left right after.