Most Helpful Guy
A guy likes you when he says a lot of dumb things because he doesn't know how to hold a normal conversation with you, he may do it perfectly with everyone else, but when it comes to you he doesn't even know how to handle it.
Also when a guy gets extra nice and goes out of his way for you, he obviously likes you, like maybe he talks about things you want to talk about as opposed to things he would love to talk.
Physically you can easily spot someone that really likes you by his voice, if his voice gets higher in picth and lower in volume he likes you a llot. He wouldn't be talking like that if he didn't like you, at the least he likes you a lot while he is doing those things without thinking.
Also guys that like you may become fidgety with his hands and lean in when he talks.
All those are clear signs that he likes you a lot with no exceptions, even if the guys is cool, confident, very popular, good in conversation, he will still show many of those signs.
If he doesn't show any of those signs, he obviously doesn't like you, but he may still have sex with you, those are different things.