Page 57 - Advanced English Grammar in Use

N e e d ( n ' t ) , d o n ' t h a v e to a n d m u s t n ' t
t o and
have
Need(n’t), don't
mustn't
Mustn't and needn't / don't have
Mustn't and needn't / don't have to to
need to)
or don't
use
is
ALLOWED and needn't
(or don't
mustn't to
say that something
NOT
We use mustn't to say that something is NOT ALLOWED and needn't (or don't need to) or don't
We
is
say that something
NOT
NECESSARY:
have to
have to to to say that something is NOT NECESSARY:
mustn't walk on the grass here.
You
2 • ¢ You mustn't walk on the grass here.
You mustn't put anything on the shelves until the glue has set hard.
• « You mustn't put anything on the shelves until the glue has set hard.
be boring.
They proved that watching a chess match needn't
• ¢ They proved that watching a chess match needn't be boring.
We needn't go into details now, but we seem to agree on the general principles.
• ¢ We needn't go into details now, but we seem to agree on the general principles.
D Need, needn't, and don't need to / don't have to to
Need, needn't, and don't need to / don't have
used
be
as
modal verb
a
or as
an ordinary verb.
Compare:
infinitive)
(before
a bare
Need can
Need can be used as a modal verb (before a bare infinitive) or as an ordinary verb. Compare:
(= modal verb)
a • ¢ You needn't speak so loudly. (= modal verb)
so loudly.
You needn't speak
if she doesn't want to.
• • * She needn't come with us if she doesn’t want to. (= modal verb)
us
(= modal verb)
She needn’t come with
She's thirsty. She needs a drink. (= ordinary verb)
• ¢ She's thirsty. She needs a drink. (= ordinary verb)
(= ordinary verb)
Jim and Bob are here. They say they need to see you urgently.
• ¢ Jim and Bob are here. They say they need to see you urgently. (= ordinary verb)
although
it is
modal verb need is most commonly used
a
is
in negative sentences,
it
When
When it is a modal verb need is most commonly used in negative sentences, although it is
sometimes also used in questions:
sometimes also used in questions:
(or,
commonly Do you have to go...?)
soon?
more
so
Need you go home
• ¢ Need you go home so soon? (or, more commonly Do you have to go...?)
Need I say more? (or, more commonly Do I have to say...?)
• ¢« Need I say more? (or, more commonly Do I have to say...?)
can use either needn't or don't have to when we say that is unnecessary to do something:
We can use either needn't or don't have to when we say that is unnecessary to do something:
We
see you, but you needn't (or don't have to) come if you're busy.
(
y ,
y
g good
It would be
• * It would be good to to see ypu, but you needn't (or don't have to) come if you're busy.
You needn't (or don't have to) whisper. Nobody can hear us.
• « You needn't (or don't have to) whisper. Nobody can hear us.
uses of needn't and don't need to.
Compare these uses of needn't and don't need to.
Compare these

give permission not to do
it later.
You
needn't cut the grass,
do
I'll
To give permission not to do • ¢ You needn't cut the grass, I'll do it later. / /
To
You
cut the grass,
I'll do it later.
don't need to
something we can use either
something we can use either • ¢ You don't need to cut the grass, I'll do it later. / /
needn't or don't need to:
needn't or don't need to:

necessity,
talk
general
about
a
To
You don't need to be over 18 to get into a disco. /
To talk about a general necessity, # You don't need to be over 18 to get into a disco. /

need
18 to get into a disco. X
to:
don't
prefer
we
You needn't be over +8-o get into a-disco-X
we prefer don't need to:
@ You-neednt-be-over
Didn't need to / didn't have to and need not have
Didn't need to / didn't have to and need not have
say that it was not necessary to do something in the past, and it wasn't done, we use
When we say that it was not necessary to do something in the past, and it wasn't done, we use
When we
in
didn't have to.
To show that we think something that was done was not,
or
need to
didn't
didn't need to or didn't have to. To show that we think something that was done was not, in
use need
necessary we
not have:
fact,
fact, necessary we use need not have:
• ¢ • ¢ Chris and June phoned to say that they couldn't come to eat, so I didn't need/have to cook
Chris and June phoned to say that they couldn't come to eat, so I didn't need/have to cook
Study how we use need with scarcely, hardly, and only, particularly in formal contexts: also
(= I didn't cook the dinner)
dinner.
dinner. (= I didn’tcook the dinner)
Chris and June phoned to say that they
I needn't have cooked dinner. Just as it was ready, Chris and June phoned to say that they
I needn't have cooked dinner. Just as it was ready,
(= I did cook the dinner)
couldn't come to eat. (= I did cook the dinner)
couldn't come to eat.
only,
formal contexts:
in
use need with
scarcely,
and
particularly
hardly,
Study how we
(= it is almost
• *
We need hardly point out that there is a water shortage at the moment. (= it is almost
We need hardly point out that there is a water shortage at the moment.
for us to point out...)
unnecessary
unnecessary for us to point out...)
(= it is almost unnecessary for me to add...)
• ¢
I need scarcely add that you will be missed. (= it is almost unnecessary for me to add...)
I need scarcely add that you will be missed.
small to make the proposals acceptable.
The changes need only be small to make the proposals acceptable.
The changes need only be
• ¢
are
'...scarcely need to add...'
'...only
and
need to be...'
'...hardly need to point out...,' ‘...scarcely need to add...' and ‘...only need to be...' are also
‘...hardly need to point out...,'
formal.
less
and
possible,
possible, and less formal.
Mustard have (got) to
Must and have (got) to =>