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Past Simple of To Do

Introduction

To do is a main verb and an auxiliary verb that is essential in grammar.

It is an irregular verb and it has its own constructions in the affirmative, negative and interrogative forms.

The past simple is the tense used to express situations, events and actions that happened in the past.

Form

To do can be used as an auxiliary verb or a main verb that has its own meaning. To do is an irregular verb and in the affirmative, negative and interrogative form in present it has different kinds of structures and forms.

To Do Affirmative

In the affirmative form, the verb to do follows this structure:
Subject + verb to do + …

In the past tense, as main verb and auxiliary verb, it has the following forms:

Subject To Do as main verb To Do as auxiliary verb 
I did do did + base verb
You did do did + base verb
He did do did + base verb
She did do did + base verb
It did do did + base verb
We did do did + base verb
You did do did + base verb
They did do did + base verb

To Do Negative

In the negative form the verb to do follows this structure:
Subject + to do + not + …

In the past tense, as main verb and auxiliary verb, it has the following forms:

Subject To Do as main verb To Do as auxiliary verb 
I did not do did not + base verb
You did not do did not + base verb
He did not do did not + base verb
She did not do did not + base verb
It did not do did not + base verb
We did not do did not + base verb
You did not do did not + base verb
They did not do did not + base verb

To Do Interrogative

In the interrogative form the verb to do follows this structure:
To do + subject +  …?

In the past tense, as main verb and auxiliary verb, it has the following forms:

To Do as main verb Subject Question Mark
Did I do?
Did you do?
Did he do?
Did she do?
Did it do?
Did we do?
Did you do?
Did they do?
To Do as auxiliary verb Subject Question Mark
Did I base verb + ?
Did you base verb + ?
Did he base verb + ?
Did she base verb + ?
Did it base verb + ?
Did we base verb + ?
Did you base verb + ?
Did they base verb + ?

Example

To Do Affirmative:

  • I did my homework.
  • He did his work diligently.

To Do Negative:

  • You did not do any sport. 
  • She did not do her work properly.

To Do Interrogative:

  • Did you do housework at home?
  • Who did this?

Use

We use the past simple of the verb to do as:

  • an auxiliary verb: before the main verb to form its negatives and interrogative forms and the negative imperatives in the past, as well as before the main verb in the affirmative form to give more emphasis in the past;
  • a main verb: in the meaning of to perform or to complete an action.

Summary

To do can be used as a main verb or an auxiliary verb.

It is an irregular verb and it has its own constructions:

  • affirmative: we start with the subject followed by the verb to do (without to) and the main verb (when it is an auxiliar verb);
  • negative: we start with the subject followed by the verb to do (without to), not and the main verb (when it is an auxiliar verb);
  • interrogative: we start with to do (without to) followed by the subject and the main verb.

For example:
He did his job well.” → the subject is followed by the verb in its past form did.
I did not do my homework in the evening.” → the subject is followed by the verb and the negative particle not.
Did he do the exercises well?“→  the past form did is followed by the subject and the main verb.