guess what/guess what?

This one you probably never even thought about, but it's surprising how often it occurs.

Can you spot the error here? "Guess what she told me?" You probably can't, and that's why it's incorrect.

Saying something such as, "Guess what?" is not a question. Why do you insist on putting a question mark at the end? You're telling someone to guess. You're not asking. If you said, "Can you guess. . .?" now you're asking. See the difference?

While I'm thinking of it, here's another one that's related: Stop saying you're going to "ask a question." Can you ask anything other than a question? You're either going to "ask," or you have "a question."

Guess what. You're now a whole lot smarter. Lucky you.