Modals

Look at the table and see the meaning, function and uses of modals:

Modals	Meaning	Expressing	Example
must	to have to	strong obligation	I must stop when the traffic lights turn red.
	to be very probable	logical conclusion (deduction)	He must be very tired after such enormous work
must not	not to be allowed to	prohibition	You must not smoke in the hospital.
can	to be able to	ability	I can swim
	to be allowed to	pertpä9iãxion	Can I use your phone please?
	it is possible	possibility	Smoking can cause cancer!
could	to be able to	ability in the past	When I was younger, I could stay up all night and not get tired.
	to be allowed to	more polite permission	Excuse me, could I just say something?
	it is possible	possibility	It could rain tomorrow!
may	to be allowed to	permission	May I use your phone, please?
	it is possible, probable	possibility, probability	It may rain tomorrow!
	it is possible,	weak possibility,	I might come and visit
	probable	probability	you in America next year if I can save enough money.
need	necessary	necessity	Need I say more?
need not	not necessary	lack of necessity/ absence of obligation	I need not buy any tomatoes. There are plenty in the fridge.
should/ ought to	used to say or ask what the correct or best thing to do	moderate obligation	I should / ought to see a doctor. I have a terrible headache.
	to suggest an action or to show that it is necessary	advice	You should / ought to revise your lessons.