Modals

List of Modals

Modal Verb	Meaning	Expressing
must	to have to	100 % obligation
	to be very probable	logical conclusion (deduction)
must not	not to be allowed to	prohibition
can	to be able to	ability
	to be allowed to	permission
	it is possible	possibility
could	to be able to	ability in the past
	to be allowed to	more polite permission
	it is possible	possibility
may	to be allowed to	permission
	it is possible, probable	possibility, probability
might	to be allowed to	more polite permission
	it is possible, probable	weak possibility, probability
need	necessary	necessity
need not	not necessary	lack of necessity/abcense of obligation
should/ought to	used to say or ask what is the correct or best thing to do	50 % obligation
	to suggest an action or to show that it is necessary	advice
	to be very probable	logical conclusion (deduction)
had better	to suggest an action or to show that it is necessary	advice