I'm sorry, I've forgotten your name.
Let me write down that date before I forget it.
I completely forgot about Jenny's party.
[ + (that) ] We had forgotten (that) she doesn't come on Thursdays.
I'm sorry, I was forgetting (= I had forgotten) (that) you would be away in August.
[ + -ing verb ] She would never forget seeing the Himalayas for the first time.
[ + question word ] I've forgotten what you do next/how to do it.
I never forget a face (= I'm good at remembering people).