In English, there are some special verbs that have certain special characteristics. These verbs
are called “modal verbs“.
1. They don’t need auxiliaries or helping verbs to make questions. If you want to make questions using a modal verb, just put the modal verb at the beginning of the questions.
2. It is not possible to use “to” (except with ought to and have to) after a modal verb.
3. The verb that follows a modal verb is always in the infinite form.
4. Never put two modals together.
Click on any modal verb below to learn how to use it.
MIGHT (50% possibility, also a soft suggestion)
MAY (50% possibility, also asking for formal permission)
CAN (ability, informal permission)
SHOULD (suggestions, also strong possibility)
OUGHT TO (suggestions, also strong possibility)
SHALL (polite proposal, formal command and a future activity)
COULD (ability in past tense, polite requests, conditional tense, 50% possibility, also a soft suggestion)
WOULD (to express desire, polite offerings, and used for conditional tense, a past habit or action)
MUST / HAVE TO (obligation, necessity, very strong possibility)
“have to” is not a modal verb but it has almost the same intensity as “must“. Must is sometimes a stronger obligation or possibility, but this depends on the context of the conversation.