A
modal verb (also
modal,
modal auxiliary verb,
modal auxiliary) is a type of
auxiliary verb that is used to indicate
modality. The use of auxiliary verbs to express modality is characteristic of
Germanic languages.
Modal verbs give additional information about the mood of the main verb that follows it. In other words, they help to incorporate or add the level of necessity (must = obligation, requirement, no choice); (should = recommendation); (can/could = it is possible); and (may/might = option, choice).
Most modal verbs have two distinct interpretations, epistemic (expressing how certain the factual status of the embedded proposition is) and deontic (involving notions of permission and obligation). The following sentences illustrate the two uses of must
Epistemic modals can be analyzed as raising verbs, while deontic modals can be analyzed as control verbs.
