Question

Auxiliary Verb : Do

'Do' is used with the main verb -

To form questions:

1. Yes/No questions
   1. Do you know the answer?
   2. Did you see the bird?
2.  Wh- questions
   1. What did she say?
   2. What does he want?

Underline the main verb in the above questions. 
Can we drop/remove the main verb from the questions?

Answer 1

• Do you know the answer?
• Did you see the bird?
• What did she say?
• What does he want? 

No, since the main verb is necessary to understand the question, we cannot eliminate it. The question will become confused and incomplete if the key verb is eliminated.