Ability: can, can't, could, couldn't

1. We form sentences with can like this:

can+ infinitive

I can ski.

Positive

I/He/She/It/We/You/They can ski

Negative Full Short
Form Form

I/He/She/It/We/You/They cannot ski can't ski.

Questions

Can I/He/She/It/We/You/They (etc) ski?

In spoken English cannot is possible, but we normally use can't:

He can't swim

2.- We use can and can't to talk about things we are able to do generally.

She can speak Japanese. (= She is able to speak Japanese)
He can't ski. (= He isn't able to ski.)

We also use can and can't to talk about things we are able to do at the moment:
I can see the moon. (= I am able yo see it now).

3.- We form sentences with could like this:

could + infinitive

I could swim

Positive

I/He/She/It/We/You/They. could ski.

Negative Full Short

Form Form

I/He/She/It/We/You/They could not ski. couldn't ski.

We use could to talk about things we were able to do generally in the past:

I could run 100 metres in 12 seconds when i was young

Susan could read when she was three years old.

4.- We do not normally use could for something that happened on an particular occasion in the past. We use was able to or managed to:

The boat was in difficulties, but in the end it managed to reach the port. (Or... it was able to reach...; Not... it could reach...)

5.- When we talk about person's ability to do something in the future, we use will be able to.

The baby will be able to talk soon.

So am I, I am too, Neither am I, etc

1. Look at this.

She is saying that she is also tired.

2.- Here are some more examples:

He was very angry. ----> So was I

My flat's quite small. -->So is mine.
They were waiting --> So was she.
I'm going to have tea --> So am I
Ann has finished her work and so has Mary.
They've been waiting. --> So has she.
I work in an office. --> So do I.
I enjoyed the film.--> So did I.
Philip will pass the exam and so will you.
He can drive. --> So can she.

Note:

----> we use so after a positive statements;
----> the verb we use after so depends on the verb used in the positive statement.

3.- Instead of so am I, we can say I am too, with the same meaning. Here are some examples:

I'm tired. ---> I am too.
We've got a small flat. ---> We have too.
I work in an office. ---> I do too.
Bill enjoyed the film and I did too.

4.- We can use expression like neither am I to reply to a negative statement:

I'm not tired. ----> Neither am I (= and I'm not tired.)
I haven't seen that film.---> Neither have I
I don't like this pleace. ---> Neither do I
I didn't see that play. ---> Neither did I
His sister can't drive and neither can he.

5.- We can say I'm not either to mean the same as neither am I:

I'm not tired. ---> I'm not either. (= And I'm not tired.)

I haven't seen that film. ---> I haven't either.
I don't like this place . ---> I don't either.
I didn't see that play. ---> I didn't either.
His sister can't drive and he can't either.

Short answers

1. Look at this example:

Question + Short Answer

Is he at work? -- Yes, he is.
Can I come? -- No, you can't.
Do you like it? -- Yes, I do.
Does she live here? -- No, she doesn't.

We call these 'short answer' because they are not 'full' answers:

Is she sick? --> Yes, she is sick. (full answer)
--> Yes, she is. (short answer)

We use short answers to reply to 'yes/ no' questions.

Are you coming? --> Yes, I am
--> No, I'm not

2. We form short answers by not using the main verb from the question:

Have they gone? -->Yes, they have gone.
Did he go to Paris? --> Yes, he did go.
Is she waiting? --> Yes, she is waiting.

When the main verb is be, we use be:

Are you tired? --> Yes, I am.

When use answer No, we use a negative verb:

Will they win? -->No, they won't.
Did Paul come? -->No, he didn't.
Are you cold? --> No, I'm not.

We never use positive short forms in short answers:

Are you tired? --> Yes, I am. ( not Yes, I'm.)
Is he happy?--> Yes, he is. ( not Yes, he's.)

3. We can also use short answers to reply 'yes' or 'no' to statements:

Statement + Reply

He's working hard --> Yes, he is.
She's at work. --> No, She isn't.
She loves films. --> Yes, she does.

Note that with Present Simple or Past Simple verbs, we use do, does or did in the reply:

She loves films -->Yes, she does.
He liked the book --> Yes, he did.

4. When we write, we normally put a 'comma' (,) after Yes or No in short answers:

He lives in London. -->No, her doesn't

Question tags

1. A question tag is a short question (e.g. isn't it? haven't we?) that we can add at the end of a statement:

Henry: We've met before, haven't we?
Jeff: Yes, we have.

2. Look at this part of a conversation:

Anna: Sandra is Swiss.
David: No, she's French, isn't she?

(= I thought she was French, but am I wrong?)


When tag question really are questions, like David's the voice up at the end.

but when tag questions are not really questions, the voice goes down at the end:

That was a boring programme, wasn't it?
(=I think that was a boring programme.)


3. Note that the verb we use in the tag depends on the verb used in the statement:

Verb + Tag

be: You're French aren't you?

verbs: He plays golf doesn't he?

auxiliary verb: It has arrived hasn't it?

Thus, most verbs use do/does, while be and auxiliary verbs use the same verb in the question tag.

4. A positive statement has a negative tag:

Positive + Negative

I'm right aren't I?
(Not am't I?)
You're 18, aren't you?
They're getting tired, aren't they?
They were friendly, weren't they?
He lives in France, doesn't he?
You speak Spanish, don't you?
You passed your exams, didn't you?
She has left, hasn't she?
You can drive, can't you?
The bus will come soon, won't it?

5. A negative statement has a positive tag:

Negative + Positive

It isn't very cheap, is it?

We aren't going to be late, are we?

She wasn't angry, was she?
You don't like this, do you?
She didn't win, did she?
She hasn't visited Ireland, has she?
She can't drive, can she?
It won't rain today, will it?