hi........there's something that always makes me confused about............i want to know the difference between using DID and HAVE in QUESTIONS....THANKS
Have you had your lunch?
As an auxiliary, you use it with the present perfect and the past perfect:
Have you eaten your vegetables? (present perfect)
Had they forgotten to book a table? (past perfect)
As you always need an auxiliary to ask a question, you use did if your question does not require another auxiliary:
Did you open the window?
Shall I open the window?
Should I open the window?
Can I open the window? etc