(someone) can tell (clause)

When you "can tell" something, it means that you are able to know it by seeing it, tasting it, feeling it, etc.:

I can tell that you're getting better at it.

Could you tell I wanted to leave?

You can leave "that" out in casual conversation, but in formal speaking or in writing you should definitely include it:

I can tell that you put a lot of work into it.

This phrase appears in these lessons: