Modal verbs are different from normal verbs:
1: They don't use an 's' for the third person singular.
2: They make questions by inversion ('she can go' becomes 'can she go?').
3: They are followed directly by the infinitive of another verb (without 'to').
Modal verbs are used to express:
Ø Probability or possibility: to say how sure we are that something happened / is
happening / will happen.
1: Talking about the present:
•
She must be on the
bus. (I'm fairly sure this is a good guess)
•
She could be lost.
(maybe)
•
She may be in the
wrong room. (maybe)
•
She might come soon.
(less probable than may) / past of may
•
She can't be at
home. (I'm fairly sure this isn't true)
2: Talking about the past: must / might / could / may / can't + have + past
participle
You: Where was
Julie last night?
David:
•
She must have forgotten
about our date. (logical conclusion about an event in the past)
•
She might have worked
late. (used hypothetically; a
guess about a past action)
•
She could have taken
the wrong bus.
•
She may have felt
ill.
•
She can't have stayed
at home. (impossible)
couldn't have +
past participle (something wasn't possible in the past, even if you had
wanted to do it)
·
I couldn't have arrived any earlier. There was a
terrible traffic jam (= it was impossible for me to have arrived any earlier).
We can also use should have + past participle to talk about
something that, if everything is normal and okay, we think has already
happened. But we're not certain that everything is fine, so we use 'should
have' and not the present perfect or past simple. It's often used with 'by
now'.
·
His plane should have
arrived by now (= if everything is fine, the plane has arrived).
We can also use this to talk about something that would have happened if
everything was fine, but hasn't happened.
·
Lucy should have
arrived by now,
but she hasn't.
Ø
Ability
1: Talking about the present: can / can't (for both general and specific ability)
•
He
can't drive.
•
We
can come now.
2: Talking about the past:
could / couldn't (for general ability)
•
I could read
when I was four.
was or were able to / couldn't (for specific ability)
•
She was able to
pass the exam, even though she hadn't studied much.
•
I couldn't open
the window.
could + have + past participle (an ability someone had
in the past, but didn't use)
• I could have played the piano well but I
didn't practise enough.
3: Talking about the future:
will / won't be able to (general ability)
•
At the end of the course, you will be able to make your own website.
Ø Obligation, Prohibition and Advice
modal verb
|
Positive
|
Negative
|
have to /
don't have to
(had to: for the past)/ needn’t
|
strong obligation (possibly from outside)
• Children have to go to school.
• She has to pay a fine.
|
no obligation =
needn’t
• She doesn't have to work on Sundays.
• You don't have to eat anything you don't
like.
|
must / mustn't
|
strong obligation (possibly based on the
speaker's opinion)
• I must study today.
|
prohibition
• You mustn't smoke here.
|
should /
shouldn't
|
advice
• You should save some money.
|
advice
• You shouldn't smoke so much.
|
Should have + past participle can mean something that would have been a good idea,
but that you didn't do it. It's like giving advice about the past when you say
it to someone else, or regretting what you did or didn't do when you're talking
about yourself. (an advice wasn’t followed)
·
I should have save some money
Shouldn't have +
past participle means
that something wasn't a good idea, but you did it anyway.
·
I shouldn’t have
spent all the money.
Ø Permission / Requests we can use verbs such as 'can', 'could' and 'may' to ask for and give
permission. We also use modal verbs to say something is not allowed.
•
Might/May I come in? / May I call you later? (very polite)
•
Could I leave early today,
please? / Could I have a coke,
please? (polite)
•
Can we swim in the lake? / Can you lend me
your pencil, please? (informal)
Ø Habits: we can
use 'will' and 'would' to talk about habits or things we usually do, or did in
the past.
•
When I lived in Italy, we would
often eat in the restaurant next to my flat.
•
John will always be late!
Ø Willingness: to talk
about something you wanted to do but didn't. This is very similar to the third
conditional, but we don't need an 'if clause'.
·
I would have gone to the party, but I was really busy. (= I
wanted to go to the party, but I didn't because I was busy. If I hadn't been so
busy, I would have gone to the party.)
MODAL
|
USES
|
EXAMPLES
|
||
CAN
|
a. General ability in the present or future
b. Possibility
c. Prohibition (can’t)
d. Request (informal)
e. Offering (informal)
f. Impossibility (negative only)
g. Permission (informal)
h. Negative deduction in the present
|
I can speak Spanish. I
can help you later.
He can lift this table
because he’s very strong
You can’t smoke here
Can I use your car?
Can I help you?
You can't see the dentist
now.
You can take the car
tomorrow.
He can’t be out. I’ve
just seen him
|
||
COULD
|
a. General ability
in the past
b. Possibility (not
certain)
c. Polite request
d. Impossibility in
the past
e. Suggestion
|
She could swim well at
the age of four.
The keys could be in the
car.
Could I have a word with
you?
I couldn't open the door.
You could get advice from
your doctor
|
||
BE ABLE TO
|
a. General ability in the
present (= can)
b. Specific past ability
managing to do something
despite difficulty
c. General ability in the
future
|
He is able to dress
himself.
We were able to find the
house although we had no map.
We will be able to visit
you next week.
|
||
MAY
|
a.
Future possibility (probability)
b.
Negative possibility ( “ )
c.
Polite request (formal)
d.
Permission (formal)
e.
Prohibition (formal)
|
It
may rain tomorrow.
He may not arrive tonight.
May I call you later?
You may take the car.
You
may not smoke in the library.
|
||
MIGHT
|
a.
Possibility ( less probable than “may”)
b.
Negative possibility
c.
Past form of may
|
It might rain tomorrow.
Tom might not be available today.
She
said that our plan might work.
|
||
SHOULD
/
OUGHT
TO
|
a.
Giving advice
b.
Asking for advice or information
c.
Telling somebody that it is right /wrong to do
something
d.
Polite suggestion when unsure of answer
e.
90% certainty / prediction
|
You
should (ought to) see a doctor.
Should
I phone the police?
You
shouldn't lose your temper with people
Should
I put the bags here?
He
should (ought to) do well in the exam.
|
||
MUST
|
a.
Obligation, future intention
b.
Orders
c.
Strong necessity
d.
Almost certainty / possitive deduction in the present
e.
Persuasion; strong recommendation
f.
Prohibition / Something forbidden (Neg.)
|
I
must write a letter to my aunt.
You
must go out
You
must observe the speed limit.
The
lights are on. She must be at home.
You
must go and see that film.
You
mustn’t smoke inside the hospital
|
||
HAVE
/ HAS TO
|
a.
External obligation / necessity
b.
lack of necessity (Neg.)
c.
past necessity
d.
future necessity
|
We have to wear school
uniforms.
We don't have to pay this
until September.
He had to leave early.
We will have to leave
soon.
|
||
NEEDN’T
|
a. Lack of necessity (=
don't have to)
|
You needn't come today if
you don.t want to
|
||
SHALL
|
a.
Polite question or offer of help
b.
Suggestions or asking for suggestions
c.
Future with I / we as subject (not common).
|
Shall
I carry this bag for you?
Shall
we meet at the entrance?
I
shall (will) find a hotel when I get there.
|
||
WILL
|
a.
Certainty, prediction
b.
willingness
c.
spontaneous decision
c.
Polite request
d.
Promises and threats
|
He
will arrive at six o'clock.
I
will marry you.
I’ll
answer the door.
Will
you pass the sugar, please?
I
will bring you a souvenir from Rome
|
||
WOULD
|
a.
Polite request
b.
Repeated past action
c.
Past form of will
d.
Expressing preference (would rather)
|
Would
you move your car, please?
I
would walk on the beach every morning.
We
wondered when he would join us.
I
would rather have tea.
|
||
NEED
TO
|
a.
Necessity
|
My
sister needs to go to the dentist
|
||
USED
TO
|
a.
Past routines
b.
Past states now finished
|
We
used to play here when we were school mates
I
used to be very shy but now I am not.
|
||
MODAL PERFECT
|
USE
|
EXAMPLE
|
||
MUST
HAVE + Past Participle (P.P.)
|
When
we are certain about past actions or draw logical conclusions
|
Paul didn't answer my
calls. He must have beenout all day.
|
||
MUSTN’T
HAVE + P.P.
CAN’T
HAVE + P.P.
|
When
we are certain something did not happen
|
He must not have
heard about the earthquake. (= can't have heard)
|
||
MAY/MIGHT/COULD
HAVE + P.P.
|
When we are not sure
because we
do not actually know what
happened in the past
|
Paul is late for work.
He may have missed the bus. He might have left his
house late.
|
||
COULD
HAVE + P.P.
|
when we had the ability
to do something in the past but we didn't do it
|
I could have gone to the party but didn't
want to.
|
||
COULDN’T
HAVE + P.P.
|
To
express that something didn’t happen the way it seemed
|
He
couldn’t have done anything wrong
|
||
SHOULD
HAVE + P.P.
|
When expectations were
not fulfilled
When sensible advice
wasn't followed
|
He should have
arrived by now, but he still isn't here.
You should have
checked the brakes on your car before starting out.
|
||
SHOULDN’T
HAVE + P.P.
|
To refer to a foolish
past action
|
You shouldn't
have taken the car without asking.
|
||
WOULD
HAVE + P.P.
|
When we were willing to do something, but didn't do
it
|
I would have
helped you, but I was away for the weekend.
|
||
WILL
HAVE + P.P. (Future Perfect)
|
When we talk about an action that
will be completed by some point in the future
|
By this time next year
I will have passed all my exams.
|
||
NEEDN’T
HAVE + P.P.
|
To
express the absence of necessity in the past
|
You
needn’t have bought anything to the party
|
||
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