An area of meaning having to do with possibility, probability, obligation and permission. In the following examples, the modal meanings are expressed by the auxiliary verbs ‘must’ and ‘may’:

• Sue may have written the note. (possibility)

• Sue must have written the note. (probability)

• You must postpone the meeting. (obligation)

• You may postpone the meeting. (permission)

Modality can also be expressed by several different kinds of words:

• adverbs (for example, ‘possibly’, ‘necessarily’, ‘certainly’, ‘perhaps’)

• adjectives (for example, ‘possible’, ‘probable’, ‘likely’, ‘necessary’)

• nouns (for example, ‘possibility’, ‘necessity’, ‘obligation’)

• modal verbs (for example, ‘permit’, ‘oblige’).