Formation of ‘to do’ in the past simple

The simple past tense (sometimes merely called past) of to do is formed irregularly and has only one form (did) – unlike its counterpart in the present tense, which has two forms (do/does). Furthermore, the verb ‘to do’ can be used as an auxiliary verb as well as a full (main) verb. Compare the formation and occurrences in the example sentences and the table below:

• Examples of conjugating ‘to do’ in the past simple as a full verb:
  • “Patrick did all his homework yesterday.”
  • “Last year I did a lot of sports.”

Auxiliary verb forms of ‘to do’ in the past simple

The tables show the forms of ‘to do’ as an auxiliary verb combined with a full verb, in this case, ‘to eat’. For example:

Positive/affirmative sentences (as an auxiliary verb)

* In regular positive statements, ‘did’ does not appear as an auxiliary verb unless particular emphasis is needed.

Negative sentences (as an auxiliary verb)

Full (main) verb forms of ‘to do’ in the past simple

These tables demonstrate the forms of ‘to do’ as a full verb together with ‘to do’ as an auxiliary verb in questions and negations:

Positive/affirmative sentences (as a full verb)

Negative sentences (as a full verb)

Further explanations relating to the ‘Formation of the simple past of ‘to do’’

The following explanations are related to the topic ‘Conjugation and verb forms of ‘to do’ in the past simple’ and may also be interesting:

• Use of the past simple
• Formation of the past simple
• Verb forms of modal verbs in the past simple
• Exercise 1: past simple