Modal verbs features: Modal verbs have more than one meaning: I can swim ability

CHAPTER 3. MODAL VERBS
Features:

• 
  Modal verbs have more than one meaning:
  

I can swim.(ability) Can I have some sugar.(request)

• 
  Modal verbs aren’t used with helping verbs:
  

I don’t must do my homework. – wrong. I mustn’t do my homework. – right.

• 
  Modal verbs usually have only present simple form and in other forms other verbs are used instead of them:
  

I can’t speak English well, now. I will be able to speak it well after I’ve finished the course.

• 
  If there is another verb after modal verbs they are used in infinitive form without “to” or “ing”:
  

May I coming in – wrong. May I to come in – wrong. May I come in – right.

• 
  Modal verbs don’t come after other verbs instead of them other verbs are used:
  

I want to can play the piano – wrong. I want to be able to play the piano – right.

• 
  Modal verbs don’t take personal suffix “s”, they are the same with all persons:
  

She can swim. I can swim. We can swim.
Structure:
P: S+M.V.+V… I may come later.
N: S+M.V.+not+V… I may not come tonight.
SH.A.Q: M.V.+S+V…? May I sit?
Yes, S(p) M.V. Yes, you may.
No, S(p) M.V.+not. No, you may not.
Q: Q.W.+M.V.+S+V…? Where should I meet you?
UNIT 8. ABILITY AND POSSIBILITY

• 
  “can (do)” is used to say that something is possible or someone has the ability to do something:
  

You can see the sea from our bedroom window. Can you speak any foreign languages?

• 
  “be able to” is possible instead of “can”, but “can” is more usual. But “can” has only two forms: can(present) and could(past). So in other forms “be able to” is used instead of “can”:
  

I haven’t been able to sleep recently. Tom might not be able to come tomorrow.

• 
  Sometimes could is the past of can. It is especially used with these verbs:
  

see hear smell taste feel remember understand:
When we went into the house, we could smell burning.

• 
  could is also used to say that someone had the general ability to do something in the past:
  

I could swim when I was seven.

• 
  But to say that someone managed to do something in one particular situation could is not possible. In this kind of situation was/were able to is used:
  

The fire spread through the building very quickly but everyone was able to escape.

• 
  The negative couldn’t is possible in all situations:
  

My grandfather couldn’t swim. We tried hard but we couldn’t persuade them to come with us.


UNIT 9. COULD (DO) AND COULD HAVE (DONE)

• 
  Could (do) is used in a number of ways. Sometimes it is the past of can (do), but sometimes it has a present or future meaning. It is used to talk about possible future actions, especially when we make suggestions:
  

A: What shall we do this evening?
B: We could go to the cinema. (can is also possible here)

Could is also used to talk about possible future happenings:
There could be another rise in the price of petrol soon. (It is possible that there will be)

Sometimes could means would be able to:

Why doesn’t Tom apply for the job? He could get it.(If he applied he would be able to get it)

• 
  The past of could (do) is could have (done). And it is used to say that someone had the ability or the opportunity to do something but did not do it:
  

We didn’t go out last night. We could have gone to the cinema but we decided to stay at home.(We had the opportunity to go to the cinema but we didn’t go)