What are the examples of how to use a question mark?
You use a question mark if the sentence is a direct question.
What time is it?
You do not use a question mark if the question is embedded, like:
I asked him what time it was.
But if the embedded part is a quoted sentence (that could be used by itself) the question mark reappears:
I asked him: "What time is it?"
You may also use a question mark (between parentheses) if you want to express doubt about something:
He seems to be a very honest (?) man.