I have seen some topics related to "Did you know?" and "Do you know?" questions, and when we use them.
My question is not when we use "Did you know?", But it is Why, Why do we need to use past form with this question?
The affirmative statement is;
- You know ...
- I know that you know how to make more money.
- You know I needed many things ...
So, the question is:
- Do you know ...
- Do you know how to make more money?
- Do you know I needed many things ...?
I think the question should be use present simple to ask about things that others know now.
So, What is the reason to use "Did you know"? Is it idiom?