Conjugation and verb forms of modal auxiliary verbs in the past simple

Table of contents – past simple of modal auxiliary verbs

On this page you will find the following:

1. Formation of modal auxiliary verbs in the past simple
2. Verb forms of ‘can, ought to, must, used to, may’
3. Examples and particularities
4. Further explanations and exercises

Formation of the past simple of modal auxiliary verbs (can, must, may, used to, ought to)

The following modal auxiliary verbs have unique forms in the past simple, which may sometimes differ in meaning. Compare the following example sentences as well as the use in the table below:

• Examples of the auxiliary verbs ‘can, must, used to, ought to’ in the past tense as they may occur in a sentence:
  • “When Jim was a child, he could speak Italian fluently.”
  • “The policeman said I had to get out of the car.”
    • Be careful when using ‘must’ – it becomes ‘had to’.
• Information: Refer to present simple of modal verbs for present tense forms.

Examples and particularities of the modal verbs ‘can, ought to, must, used to, may’ in the past simple

The following example sentences show the use of the modal verbs in the past (simple). Consider the particularities, which some modals offer:

• ‘can’ has ‘could’ in the past simple and the substitute form ‘was/were able to’; examples:
  • “He could easily win every race when he was young.”
  • “I was able to get in without a ticket.”
    • There is a slight difference in meaning between both forms. See ‘can’ and ‘be able to’ to learn the details.
• ‘must’ can form the past simple only with the alternative form ‘had to’ or ‘had got to’:
  • “I had to pay the bill.”
  • “She received an emergency call and had got to go early.”
• ‘may’ has the substitute form ‘was/were allowed to’ or the actual past ‘might’:
  • “We were allowed to pass.”
  • “She said she might move to Australia.”
    • ‘may’ can also become ‘might’ for grammatical reasons (see the difference ‘may/might’).
• ‘used to’ (consult ‘used to’ for the usage in detail). Note that this form is neither possible nor does it exist in the present tense:
  • “I used to go jogging every day.”
  • “He didn’t use to go out.”
  • “We used not to go to parties.”
• ‘ought to’ is only occasionally utilized; in most cases, ‘should’ is preferred instead:
  • “We ought to get home early.”
  • “This ought to be enough.”
  • “They ought to study the language.”