Do, Does or Did

The words do, does and did often cause confusion in the English language.

They are all forms of the verb to do.

The verb to do can be used as an action verb and also as an auxiliary verb.

to do as an Action Verb

In some cases, to do is used as a verb that expresses an action (just like the verb to walk).

Subject/Verb Agreement Using to do as an Action Verb

Spelling Tip

In Present Simple 3rd person (he, she, it), add an es to a verb that ends in ‘o’:

do does / go goes

Examples

Pete always does his taxes on time.

Volunteers do a lot of work around the town.

Gil did a great job on his history report for school.

You have done nothing all morning!

I am doing the best I can!

The verb to do as an auxiliary verb

It is also common to use do, does and did as auxiliary verbs (or helping verbs) together with another verb in its base form. This is used to create negative sentences, questions, or for adding emphasis.

Negative sentences with do not, does not and did not

When creating negative sentences, we usually use shortened forms: don’t, doesn’t and didn’t together with the base form of the verb.

Note: Save the long forms (do not, does not and did not) for when you want to create emphasis. When speaking, you would put an accent on the ‘not’.