Study materials
Look at these three sentences. The verb has not changed once.
I can swim. She can swim. They can swim.
Can is the same for every subject (I, she, they). It needs no s ending, no to after it and no do in a question. It is the simplest verb in the language.
The three jobs of can
There are not many meanings, and they are all close to one another: something is possible.
| What it expresses | Example |
|---|---|
| ability | She can dance. |
| possibility | We can go now. |
| impossibility | I can't come. |
The negative is can't, and in speech it is nearly always that rather than the full cannot.
He can't drive.
Questions without a helper
To ask a question, can simply moves to the front. Do is not wanted here.
Can you swim?
Where can we sit?
Answers are short and repeat can itself: Yes, I can. No, I can't.
The same word makes requests and offers. Can you is a request to another person; Can I asks permission for yourself.
Can you open the window, please?
Can I use your phone?
The imperative: a verb with no subject
When you give an instruction, the sentence starts with the action itself. The word you is left out: it is obvious who you are talking to.
Turn left.
Sit down, please.
Don't touch that.
The word please softens the instruction and can stand at either end. And when you invite somebody to do something together with you, let's takes over.
Let's go home.
The mistakes everyone makes
The first is putting to after can.
I can to play the guitar. → I can play the guitar.
The second is adding an s in the third person.
She cans swim. → She can swim.
The third is calling in do for a question.
Do you can swim? → Can you swim?
All three are caught by one thought. Can is already a helper in itself, so no extra words are needed around it.
Try it right now
Say in English what you can do well and what you cannot do at all.
Then ask somebody for something with Can you, and give one short instruction with no subject.