Which of these are correct, please?

When you are making sure someone understands, which of these are correct:

  1. Do you hear me?
  2. Did you hear me?
  3. Do you hear?
  4. Do I make myself clear?
  5. Did I make myself clear?
  6. Have I made myself clear?

Many thanks.

All are OK, but these, “Did I make myself clear?/Have I made myself clear?” are the most fitting, presuming you have been explaining something to someone.

Thanks for your reply, but what does " do I make myself clear" imply? Is there any difference from “did I make myself clear”?

Thanks again.

It means, “Has the listener fully understood what has been said to him?” Both have the same meaning.

thanks again!
Good luck in all you do!

Yep - all are good.

#4 is better to use than #5, although they mean the same thing in conversation.