Modal Verbs

Modal verbs are small verbs that change the meaning of the main verb. They can show ability, permission, necessity, advice, offers, and requests. After a modal verb, English uses the base form of the main verb.

Can shows ability in the present. Could shows ability in the past and can also show a general possible ability. These modal verbs come before the main verb.

Can, could, and may can ask for or give permission. Could is more polite than can. May is often more formal than can.

Must and have to show necessity or obligation. Must often shows a strong rule or the speaker's idea of what is necessary. Have to often shows a rule, situation, or requirement from outside the speaker.

Should and ought to show advice or suggestion. They say what is a good idea or the right thing to do. Ought to is less common than should but has a similar meaning.

Modal verbs can make offers and requests sound polite. Can and could are common for requests. Shall can be used for offers or suggestions, especially with I and we.

After a modal verb, the main verb stays in the base form. The main verb does not take to after most modal verbs. The main verb does not change for he, she, or it after a modal verb.

To make a negative modal statement, add not after the modal verb. Some negative forms have common short forms. Negative modals show no ability, no permission, no necessity, or advice against something.

To form a question with a modal verb, put the modal verb before the subject. The main verb stays in the base form. Do does not come before the modal verb in these questions.

You can now use modal verbs to talk about ability, permission, necessity, advice, offers, and requests. You can make statements, negative forms, and questions with modal verbs. You can also use the base form of the main verb correctly after a modal verb.