Modal Forms
Listed below is a general outline of modal forms and their possible time reference.
| Examples | Form | Time Reference |
| He can answer your question. They should leave early tomorrow. He had to leave at 7 this morning. |
MODAL Simple Verb |
Present Future Past |
|
He might be joking! |
Modal Continuous Form |
Present
|
|
She can't have been serious!
|
Modal Verbs Present Perfect | Past |
| They might have been working at that time | Modal Present Perfect Continuous Verb | Past |
Modal Forms
Can / Could / Be Able to (ability, permission)
Must / Have to - Mustn't / Not Have to

