Modal verb
A modal verb (also modal , modal
auxiliary verb , modal auxiliary ) is a
type of auxiliary verb that is used to
indicate modality that is,
likelihood, ability, permission, and
obligation..
[1] Examples include the
English verbs can /could , may/
might , must , will/would, and shall/
should .
In English and other
Germanic languages , modal verbs
are often distinguished as a class
based on certain grammatical
properties.
Function.
A modal auxiliary verb gives much
information about the function of the main verb that it governs...
Modals have a wide variety of
communicative functions, but these functions can generally be related to a scale ranging from possibility
("may") to necessity ("must"), in
terms of one of the following types
of modality:
Epistemic modality, concerned
with the theoretical possibility of propositions being true or not true (including likelihood and certainty)..
Deontic modality... concerned with possibility and necessity in terms of freedom to act (including permission and duty)