Modal verbs show possibility, intent, ability, or necessity and are used together with the main verb. Modal verbs include can, could, must, might, will, would, may, have to, and should. As auxiliary verbs, modal verbs do not change form or require additional auxiliaries, and are followed directly by the bare infinitive verb without "to". Modal verbs are used to express hypothetical conditions, permission, suggestions, obligations, abilities, and possibilities.