Modal auxiliary verb

The English modal auxiliary verbs are

• will and would
• shall and should
• may and might
• can and could
• must
• ought to

Modal auxiliary verbs help other verbs express a meaning or an idea but have no meaning by themselves. In English, modal auxiliary verbs are defective; for example, they do not have participle forms (no -ing or -ed endings).

They are used in a variety of grammatical moods such as the conditional mood, which expresses uncertainty ("I would be delighted if you came to my party").