1. Modal verbs General rules
Can
Could
May, might
Must
Should= ought to
SEMIMODAL: need
Followed by+ inf without to
No"-s" in the 3rd
p.sg.
They act as auxiliaries.
WE WILL ALSO SEE:
Be able to
Have to
Be allowed to
Had better

2. CAN
CAN
FUNCTIONS EXAMPLES
Ability
Ask/give permission
Offer
Request
I can play the piano.
Can I go to the toilet? Yes, you can.
Can I offer you a glass of wine?
Can I have a glass of water?
CAN’T
Prohibition
Impossibility
/deduction
You can’t smoke in here.
(John is on holiday in Tenerife. You are
waiting for your friends to go out. Some
of your friends see someone coming…)
A: Look! John is coming !!
B: He can’t be John. He is in Tenerife!

3. COULD
COULD
FUNCTIONS EXAMPLES
Past ability
Possibility
Condition
Suggestion
Polite request
I could run ten miles in my twenties.
John could be the one who stole the money.
If I had more time, I could travel around the world.
We could spend our vacation in Hawaii.
Could I borrow your stapler?
Present Past Future
She can speak 5
languages.
She could speak 5 languages at
school.
be able to

4. BE ABLE TO
TENSES EXAMPLE
Present
Past
Future
She is able to speak 5 languages.
They were able to get tickets for the concert .
Jack will be able to come next week.
TO BE ALLOWED TO
FUNCTIONS EXAMPLES
Give permisssion
Prohibition
You are allowed to use your camera here.
You aren’t allowed to smoke in here.

5. MAY/MIGHT
FUNCTIONS EXAMPLES
Possibility
Request
Jack may be upset (I am not sure). I can't really tell if he is
annoyed or tired.
May I borrow your eraser?
TRY THESE EXAMPLES!!!
I may/might fail ………………………… subjects this term.
I may/might go to ……………………………..…this summer.
I may/might present …….to my friend /parents/mother
at Christmas.

6. MUST
FUNCTIONS EXAMPLES
Obligation (imposed by
the speaker).
Certainty
/deduction
Strong
recommendation
I must study Maths this afternoon.
You have arranged an appointment with Sue at 6. It’s six
o'clock now and someone rings the bell.
-It must be Sue. (you are sure).
You must take some time off and get some rest.
MUSTN’T
Prohibition You mustn’t smoke in this High School.

7. HAVE TO
FUNCTION EXAMPLES
External obligation She has to wear uniform in this high school.
They have to show their I.D Card before entering.
DON’T HAVE TO= NEEDN’T
FUNCTION EXAMPLES
Lack of obligation You needn’t make your bed in a hotel.
You don’t have to wake up early on Sundays

8. SHOULD= OUGHT TO
HAD BETTER
FUNCTIONS EXAMPLES
Give advice
Strong recommendation
You should/had better focus more on your family and
less on work.
You shouldn’t/oughtn’t to smoke so much.
You had better not smoke so much.
When you go to Berlin, you should visit the palaces in
Potsdam.

9. REPHRASING
If I were you I would tell him the truth.
Example: You should tell him the truth.
It isn't necessary for her to phone me back.
Perhaps we'll go swimming tomorrow.
I think Mary is probably at home because the windows are open.
Perhaps we'll rent our house in summer.
It's absolutely necessary that we finish the article today.
You cannot smoke in the underground; it's forbidden.
It is essential that we talk before the meeting starts.
Why don't we go on a camping trip?
Let's go to “Diagonal Mar”!
It isn't necessary for us to book a table; I know one of the waiters.
It's forbidden to drive without fastening your seatbelt.
If I were you I'd do some more exercises.
Perhaps I go on holiday to Menorca.
It's compulsory for all students to attend lessons.
It's possible that they move to Australia.
You are not allowed to use the phone without permission.

10. REPHRASING
If I were you I would tell him the truth.
Example: You should tell him the truth.
It isn't necessary for her to phone me back.
Perhaps we'll go swimming tomorrow.
I think Mary is probably at home because the windows are open.
Perhaps we'll rent our house in summer.
It's absolutely necessary that we finish the article today.
You cannot smoke in the underground; it's forbidden.
It is essential that we talk before the meeting starts.
Why don't we go on a camping trip?
Let's go to “Diagonal Mar”!
It isn't necessary for us to book a table; I know one of the waiters.
It's forbidden to drive without fastening your seatbelt.
If I were you I'd do some more exercises.
Perhaps I go on holiday to Menorca.
It's compulsory for all students to attend lessons.
It's possible that they move to Australia.
You are not allowed to use the phone without permission.