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, ...

These are useful verbs that are always followed by an infinitive. They are usually used in the present, imperfect, past tense with a past participle or in the conditional tense.

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, ...