Imagine trying to speak without expressing possibility, permission,or necessity; it would be like painting without colour. That’s were the modal verb step in. These special helping verbs—can, could, ...

Modal verbs, which express a likelihood, ability, permission, request, order etc., usually help main verbs to state the future. It is the reason they are categorised as auxiliary verbs in the context.

Here s a set of basic but tough grammar questions posted in Jose Carillo s English Forum by an Iran-based member who goes by the cryptic username r_a: What are the differences between a helping verb, ...