Subject Verb Agreement

[Guest]

MGmat Sentence Strategy guide Pg 13. Lists the following sentence as correct.

Does Everyone have his(or her) book?

In the above sentence since the subject Everyone is singular shouldn't we use the singular verb has instead of have

- Does Everyone has his(or her) book?

[esledge]

The verb is not just "have." To see what I mean, turn this from a question into a statement.

Everyone does have his or her book.

Does is singular, Do is plural:
He does his own yardwork.
They do their own yardwork.

To ask the question in plural form: Do all the students have their books?
The corresponding statement: All the students do have their books.