MODAL VERBS

CAN

COULD

BE ABLE TO

MAY

MIGHT

MUST
OR MUSTN'T

HAVETO/ HAS TO
DON'T/DOESN'T HAVE TO

SHOULD

OUGHT TO

MODAL PERFECTS

can't have

could have

may (not) have / might (not) have

must have

should have /

ought to have /

shouldn't have

needn't have (British)
Don't have to (American)

didn't have to

(Semimodal)

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