Can guys tell when a girl likes them?

it depends. . on the signals your giving us and how much we know about girls. some girls make it so obvious but the problem maybe that we don't know how to reacted. some girls try to make us notice but us guys are a lot slower than females. so more than likely the guy you trying to impress doesn't notice your efforts. its not our fault we clueless when we young.
or is it? lol.
its a know fact that girsl are tipically smarter and mature faster than guys.
in my opinoin girls are surpriour to guys.

Nope, guys are brain-dead when it comes to knowing if a girl likes them.

No. In a psychological sense, men typically perceive women's actions toward them in a "I-want-to-bone-your-brains-out" manner. Even if you are just asking for the time. With that said, guys have a hard time deciphering between flirting and just normal everyday nonsexual social interaction.

I've been pursuing the same girl for the last 6 months. She has a boyfriend but since we knew each other before and I did ask her out 3 years ago, she should know by now how I still feel about her. I even remind her all the time seriously. But she has not given me a single clue to show me that she feels the same. Maybe it's because she currently has someone in her life but the only thing that I know for sure is that she doesn't want me to just go away. I'm sticking around for my own reasons but it would be nice to find out if she's keeping me around for a real reason not just to continue to get to know each other.

No, I think guys are much slower at picking up on the fact that a girl likes them. With the guy I like right now, he hasn't asked me to hang out yet and I'm like 95% sure he likes me, but I'm not sure if he picked up on the fact that I like him, so I had to do something to kick it up a notch. Here's hoping it works! I'm convinced I need a big ass sign that says "HEY YOU! YEAH YOU! I LIKE YOU!"