Modal verbs are verbs that indicate likelihood, ability, permission or obligation. Modal verbs change the intention or meaning of the main verb in a sentence by showing whether an action is: Learn ...

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.