Transcript 60330x - WebLiessin

General Revision
Modal Verbs
What are modal verbs?
• Modals (also called modal verbs, modal
auxiliary verbs, modal auxiliaries) are special
verbs which are different from normal verbs
like "work, play, visit...“
• They give additional information about the
function of the main verb that follows it.
Use of modal verbs:
• Express functions such as:
• Permission
• Ability
• Obligation
• Prohibition
• Lack of necessity
• Advice
• possibility
• probability
Modal verbs are followed by an infinitive
without "to“:
Examples:
• You must stop when the traffic lights turn red.
• You look awful! You should see a doctor.
• Exception:
• You ought to go to the doctor.
Modal Verb
must
must not
can
Meaning
to have to
100 % obligation
to be very probable
logical conclusion
(deduction)
not to be allowed to
prohibition
to be able to
ability
to be allowed to
permission
it is possible
to be able to
could
to be allowed to
it is possible
to be allowed to
may
might
Expressing
it is possible,
probable
to be allowed to
it is possible,
probable
Example
I must stop when the
traffic lights turn red.
He must be very tired
after such enormous
work
You must not smoke
in the hospital.
I can swim
Can I use your phone
please?
possibility
Smoking can cause
cancer !
ability in the past
When I was younger I
could stay up all night
and not get tired..
more polite
Excuse me, could I
permission
just say something?
possibility
It could rain
tomorrow!
permission
May I use your phone
please?
possibility, probability It may rain tomorrow!
more polite
permission
weak possibility,
probability
Might I use your
phone please?
I might come and visit
you in America next
year, if I can save
enough money.
Modal Verb
Meaning
Expressing
Example
necessary
necessity
Need I say more?
not necessary
lack of necessity/absence I need not buy any
of obligation
tomatoes. There are
plenty in the fridge.
need
need not
should/ought to
had better
used to say or ask what is 50 % obligation
the correct or best thing to
do
I should / ought to see a
doctor. I have a terrible
headache.
to suggest an action or to advice
show that it is necessary
You should / ought to
revise your lessons
to be very probable
He should / ought to be
very tired after such
enormous work
logical conclusion
(deduction)
to suggest an action or to advice
show that it is necessary
You 'd better revise your
lessons
GOLDEN RULES ABOUT MODAL
VERBS
• Modal verbs never add an -s in the third person
singular:
– He must work harder to pass his exams
• Modal verbs don’t need auxiliaries to make
negative sentences or questions:
– Should I apologise?
– I mustn´t smoke in hospitals
• Modal verbs only have one form. You need other
verbs to express the same thing in the past,
future etc.
– I´ve been able to finish on time.
EXPRESSING ADVICE
• We use should and ought to to express advice
or make recommendations:
You should eat less fat if you want to lose
weight.
• You ought to relax if you don´t want to get ill.
• You shouldn´t be rude to anybody.
• You oughtn´t to tell lies.
EXPRESSING OBLIGATION OR NO
OBLIGATION
• We use must and have to to express
obligation.
• The difference between them is:
We use must when the obligation is inside the
speaker. It is a moral obligation.
• We use have to when the obligation is outside
the speaker. It comes from the situation.
EXPRESSING OBLIGATION OR NO
OBLIGATION
• I must do some exercise to get fit.
• We have to be quiet in class. That’s the rule.
Note: Have to is not a modal verb.
We use don’t / doesn’t have to, needn’t and don’t
/doesn’t need to to express no obligation.
• You don’t need to get up early. It is Sunday!
• She doesn’t need to wear a coat. It is warm outside.
• She needn’t cook tonight. We´re eating out.
EXPRESSING PROHIBITION
We use mustn’t to express prohibition.
• Children under 16 mustn’t go in there.
At school we mustn’t smoke.