Modals – can, can’t

Can/can’t are followed by the base form without the preposition “to”. This modal verb doesn’t change in the third person singular.

Affermative	Interrogative	Negative	Interro-negative
I can	Can I?	I can’t (can not)	Can’t I? (Cannot I?)
You can	Can you?	You can’t	Can’t you?
He, she, it can	Can he, she, it?	He, she it can’t	Can’t he, she,it
We can	Can we?	We can’t	Can’t we?
You can	Can you?	You can’t	Can’t you?
They can	Can they?	They can’t	Can’t they?

Can is used to express ability, to ask for permission, to ask for or to offer help to do something. Can’t is used to express refusal, to deny somedoby to do something or to make deductions.

Use	Examples
To express ability	She can speak three languages He can run a mile in less than 5 minutes
To ask for permission	Can I use your laptop?
To ask for help	Can you help me carry my luggage?
To offer to do something	We can do all the housework for you next Sunday.
To express refusal	She can’t borrow my tablet without my consent. They can’t go out without tidying up their bedrooms first.
To make deductions	It takes over half an hour walking to the station. He can’t be already there. He’s just left home.
To make suppositions	Cheap clothes can’t be of top quality material. If she can speak Russian may she can understand Ucranian too.