Auxiliary Verbs : To do

The conjugation of to do is as follows:

The uses of to do as an auxiliary verbs are:

a) Formation of questions and negative sentences

• I don't see anything.
• I don't think you know me.
• Does she go to her gymnastic classes on Mondays?

b) Formation of negative imperative sentences.

• Don't go there.
• Don't let him go out so late.
• Don't go. Stay at home and rest up.

Note: if you want to be really polite, you can use do in positive imperative sentences too.

• Do come.
• Do be quiet.
• Do sit down.

c) Emphasis, used to stress what we're saying.

• I do think he is foolish.

• Do come in!