Uses
What modal verb do we use to express probability?
May
Might
Could
What modal verb do we use to express lack of obligation or necessity?
Don't have to
Don't need to
Needn't
What modal verbs we use to express a positive deduction?
Must
What modal verbs we use to express a personal obligation?
Must
What modal verbs we use to express prohibition?
Mustn't
Can't
What modal verbs we use to express possibility in the past?
May+ have + past participle
Might + have past + participle
Could + have past + participle
What modal verbs we use to express an external obligation?
Have to
Must in formal and written English.
What modal verb do we use to give advise or a suggestion?
Should
Ought to
Had better
What modal verbs we use to express a negative deduction?
Can't
What modal verbs we use to express regret about something that did not happen?
Should + have + past participle
What modal verbs we use to express regret about something that happened?
Should not + have + past participle
What modal verbs we use to express a negative deduction in the past which certainly did not happen?
Can't + have + past participle
Couldn't + have + past participle
What modal verbs we use to express necessity?
Need to
What modal verbs we use to express improbability?
May not
Might not
What modal verbs we use to express a positive deduction in the past which certainly happened ?
Must + have + past participle