LANGUAGE REFERENCE
114
7
GRAMMAR
G1
OBLIGATION
MUST
AND
MUSTN’T
Use
must
to say that it is necessary to do something.
You
must switch
your phone
off
during the lesson.
The negative
mustn’t
means that it is necessary NOT
to do something.
We
mustn’t bring
food or drink into the classroom.
You
mustn’t take
anything from the crime scene.
SHOULD
Use
should
to recommend doing something or not
doing it.
You
should say
it again. I don’t think he heard.
You
shouldn’t use
your phone in a restaurant.
Must
and
should
are modal verbs. You use modal
verbs with other verbs to talk about obligation,
ability, possibility, etc.
Must
expresses obligation.
Should
expresses recommended actions.
A modal verb always comes before an infinitive
without
to
.
I
must phone
my mother this evening.
The forms
must
and
should
do not change after
he/she/it
.
James
must visit
his family this weekend.
She
shouldn’t call
him again.
Form questions with modal verbs by putting the verb
before the subject of the question.
What time
must we get
the bus?
(DON’T) HAVE TO
You can also use
have to
/
has to
to say that it is
necessary to do something.
Forensic scientists
have to be
very careful in
their work.
The negative
don’t have to / doesn’t have to
means
that it is NOT necessary to do something.
You
don’t have to study
law to be a scientist.
It is possible to use
must
to ask a question, but it is
often better to use
Do/Does … have to …?
Must I sign
the form too?
Do
you
have to leav
e
now?
Does
he
have to analyse
the evidence?
MUST
AND
HAVE TO
Must
and
have to
have very similar meanings.
They both mean something is necessary.
You usually use
must
when you believe that
something is important (it is your opinion).
I
must get up
early tomorrow.
You usually use
have to
to talk about rules and laws
(i.e. someone else thinks it is important).
We
have to get
a visa to visit the United States.
!
Remember that the negative of
must
(
mustn’t
) and
have to
(
don’t/doesn’t have to
) are very different.
You
mustn’t use
your mobile phone in the cinema.
(= it is not allowed)
You
don’t have to use
your mobile phone – use my
office phone. (= it is not necessary)
G2
HAD TO
AND
COULD
Must
does not have a past form. To talk about
something that was necessary in the past, use
had to
.
The doctors
had to operate
to save his life.
In negative statements, to say that something was not
necessary, use
didn’t have to
.
We
didn’t have to pay
for the tickets – they were free.
Use
Did … have to …?
to ask if something was
necessary.
Did you have to wear
a uniform to school?
Use the modal verb
could
to talk about ability in
the past.
I
could run
fast when I was younger.
You use
couldn’t
to say that you were not able to do
something or that it was not possible.
I
couldn’t finish
the book – it was really difficult.
We
couldn’t study
astronomy at our university.
Use
Could …?
to ask about ability in the past.
Could you understand
that lecture on physics
yesterday?
KEY LANGUAGE
KL
DEVELOPING AN ARGUMENT
This
caused
a revolution in knowledge.
It
meant that
ideas could spread.
It
led to
education for everyone.
It’s
connected to
the production of books.
…
so
people had to learn to read.
This
means that
society is more literate.
VOCABULARY
V1
CRIME
analyse, analysis, analyst, burglary, commit, crime,
discover, DNA, evidence, fingerprints, investigator,
reveal, scene, solve (a crime)
V2
SUBJECTS
astronomy, biology, chemistry, economics, history,
mathematics, medicine, physics
V3
NOUNS, ADJECTIVES AND VERBS WITH
PREPOSITIONS
afraid of, belong to, connected to, happen to,
a history of, interested in, lead to, proud of,
receive from, have a (good) relationship with,
separate from, spend (money) on, successful in,
thanks to
