How do I know that I should choose V.T.B or V.T.D in the question sentences?

English as a Second Language English for Beginners
1

Hello everyone

I want to know that I should choose V.T.B or V.T.D in the question sentences?
For example, “What do you think?” and “What are you thinking?”
Why in the first sentence use V.T.D and the second sentence use V.T.B ?

Thank you for your answer.

P.S. I’m not good at English. If you have more tip, please tell me.

2

Hi

I dont understand completely your question???
for example V.T.D and V.T.B

3

Me neither