+181.+ _Do_ and _did_ are used as helping verbs to give emphasis--to
form emphatic verb phrases. _Do_ is the present time form and _did_ the
past time form, as for example:
I do wish you would come.
I did hope he would win.
+182.+ When we use the negative _not_ we use the helping verbs _do_ and
_did_ to form our verb phrases. For example, we do not say:
I obey not.
I walked not.
He comes not.
They arrived not.
But in expressing the present and past time forms with the negative
_not_, we say instead:
I do not obey.
I did not walk.
He does not come.
They did not arrive.
+183.+ We also use _do_ and _did_ with the present and past time forms
of the verb in writing interrogative sentences. For example, we do not
say:
Comes he with them?
Studied you yesterday?
Found they the book?
Think you it is true?
But we say instead:
Does he come with them?
Did you study yesterday?
Did they find the book?
Do you think it is true?