modal auxiliary
Học thuậtThân thiện
Definition
Noun A type of auxiliary verb that is used to express modality—the speaker's attitude toward the action or state described by the main verb. Modal auxiliaries convey ideas such as possibility, necessity, permission, ability, and obligation.
Usage
Modal auxiliaries are used with the base form (infinitive without "to") of a main verb to modify its meaning. They do not change form (e.g., they do not add "-s" for third-person singular) and are followed directly by the main verb.
Examples
- You should for the exam. (expresses advice/weak obligation)
- She can three languages. (expresses ability)
- It might later. (expresses possibility)
- We must this project today. (expresses strong necessity/obligation)
- May I early? (expresses permission)
Advanced Usage
- Expressing Deduction/Certainty: Modal auxiliaries can indicate the speaker's level of certainty.
- That must be the postman. (high certainty)
- He could be at home. (low certainty)
- Past Forms: Some modals have specific forms to talk about the past (e.g., , , , ), while others use a perfect infinitive structure (e.g., , ).
- I could run fast when I was young. (past ability)
- She must have forgotten our meeting. (deduction about a past event)
Variants and Related Words
- Modal Auxiliary Verb: A full, more formal term for "modal auxiliary."
- Modal Verb: A common, shorter synonym.
- Semi-Modal: A verb phrase that functions similarly to a modal auxiliary but may change form (e.g., , , ).
- I have to go. (expresses external obligation, similar to must)
Synonyms
- Modal verb
- Helping verb (this is a broader category that includes non-modal auxiliaries like , , )
Related Phrases
- Modal Perfect: A structure using a modal auxiliary followed by "have" and a past participle to discuss the past (e.g., , ).
- You should have told me. (expresses a past obligation that was not fulfilled)
Noun
- an auxiliary verb (such as `can' or `will') that is used to express modality