Basic Grammar Step by Step Second Edition
Mary W. Ng
Chapter 41
Modal Auxiliary Verbs
Auxiliary verbs are words that help the main verb express an action or condition.
Modal auxiliary verbs are auxiliary verbs that we use with the base form of the main verb to talk about ability, permission, willingness, possibility, obligation or deduction. We also use modal auxiliary verbs to ask for and give advice, make suggestions, requests or offers. The modal auxiliary verbs are: can, could, may, might, must, ought to, shall, should, will and would.
| We can swim. |
| Could I use your telephone? |
| It may rain tonight. |
| I might see you tomorrow. |
| You must return this book. |
| You ought to sleep. |
| Shall we wait for you? |
| You should work harder. |
| Will you please open the window? |
| Would you dine with us? |
A modal auxiliary verb has only one form. It has no present or past participles. We use the same form with all nouns and personal pronouns.
| Tom can skate. |
| They can skate. |
We always place the modal auxiliary verb before the main verb in a statement.
| Subject | Modal Auxiliary Verb | Main Verb |
|---|---|---|
| He | can | swim. |
| I | should | rest. |
The modal auxiliary verb changes places with the subject in questions.
| Modal Auxiliary Verb | Subject | Main Verb |
|---|---|---|
| Can | he | swim? |
| Should | I | rest? |
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