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.


Modals – can, can’t