When should I use the auxiliary verb DO?
What is the difference between subject and object questions?
A SUBJECT question is asking WHO the subject of the sentence is; or WHAT he / she / it is doing.
i.e. “Who lives here?” – WHO is the subject of the sentence and is the person who lives here.
To make a subject question, we don’t need to change the order of the words and we don’t need to use the auxiliary verb DO. We just put the question word, (who / what / where / why, etc.) at the beginning of the question.
|Q. Who are you?||A. I’m a new student.|
|Q. What are you doing?||A. I’m reading a book.|
|Q. Why are you crying?||A. It’s a sad book.|
An OBJECT question is asking about the person or thing that is having the action done to him / her / it.
i.e. “Where do you live?” – WHERE is the object of the sentence, and so we need to use the verb DO.
The object question is no longer about YOU (the subject) but it’s about WHERE (the object) you live.
|Q. Where does he come from?||A. He’s from India.|
|Q. What do you like about English?||A. It’s easy to learn.|
|Q. When does the class start?||A. In about 20 minutes.|
So, remember that in an object question we should always use an auxiliary verb.
We cannot say: “Where lives John?” We must say: “Where does John live?”
An easy way to remember the difference between subject and object questions is the Love Triangle:
THE LOVE TRIANGLE
JOHN — MARY — PAUL
JOHN LOVES MARY — MARY LOVES PAUL