Modal verbs: general points

Modal verbs are with unique charcteristics. They work with the main verb to add extra meaning to a sentence, such as obligation or permission.

Structure:

Modal verbs share the following characteristics:

We put an infinitive without to after most modal verbs (but not ought to).

• I must look for my passport.
  BUT I ought to call my friend.

Modal verbs do not take -s in the third person.

• He can speak English.

Modal verbs do not use the auxiliary verb do/does to form negatives, questions or short answers.

• She shouldn't work so hard.

Modal verbs can use contractions with negatives.

• We shouldn't spend so much money.

Modal verbs only have one form. Therefore, to express different tenses, we sometimes have to use other verbs with similar meanings.

• He might take a gap year next year. They thought he was probably going to take a gap year.

Use:

Many modal verbs have several different meanings, depending on their context.