How can you tell if someone has a crush on you?

[seblayms]

[just_a_potato]

When their eyes get super big and they start drooling puddles

But seriously you can't actually "tell" if someone likes you unless you directly asked them, but there are hints that people look for which you'll probably get from other responses on your question.

[fallen_wings]

Wow, it really depends.
Usually they wouldn't stop looking at you, get nervous around you, want to stay around you most of the time, try to get your attention on something they're good at.

[Avicenna]

It's usually obvious, but they are really nice to you and want to spend a lot of time with you.

[lelastephens]

Usually by how often they look at you if you catch them starring or looking at you more in a group setting that generally means that they like you

[unluckyplant710]

I’m old enough that it’s no secret buddy.

[Aiko_E_Lara]

They tell me awkwardly

[bebelabs]

Sometimes... They start to tease you or annoy you