Introduction to modals

The modal verbs are:

• are followed by the bare infinitive
You should call Stella.

• do not have an infinitive

Like modals, ought to doesn’t change.
Have to and need to change for person and tense like normal verbs and have infinitives.

We form questions with modal verbs like this:
✓ Can you understand what he's saying?

We use modals with the passive voice like this:
✓ The address should be written clearly on the front of the envelope.