English Grammar Step by Step
Insert the appropriate modal verb in the spaces provided.
When there is a verb in brackets, put it into the correct
1 Examples: (ability)
She can play the cello/She is able to play the cello.
When I become an architect, I’ll be able to draw plans.
He has been able to calculate the cost of building
and the material needed since he became a quantity surveyor.
Can usually has a present meaning. Be able to is necessary
when can is impossible, ie in future tenses, perfect tenses,
and so forth.
a She __________ memorize a lot of things just at one glance.
b When the day breaks, we __________ reach the top of the
c He __________ play volleyball since he was a kid.
d You used to __________ persuade people to do things.
e I __________ speak and write five languages.
2 Examples: (past ability)
As a girl, I could/was able to run and jump all day without
On that occasion, I was able to escape/I managed to
escape/I succeeded in escaping her clutches.
On that occasion, I couldn’t/wasn’t able to escape her
Last night I could hear what my neighbours were talking about.
The first sentence implies a general ability in the past.
In the second, we are referring to a particular situation.
In the negative and with perceptions verbs, we normally
a When I entered the hut, I __________ see that somebody
had just been there.
b He was attacked by two men with a strong constitution
last night, but he __________ beat them up.
c When he was eighteen, he __________ sing and dance
d Last night I __________ convince my parents to allow me
to see that late-night horror film.
e I asked her to jump into the water, but she said that
she (not) __________ swim.
She could/would be able to help us if she were/was
alive. (present or future)
She could have helped/would have been able to help us
if she had been alive. (past)
Note the use of could and be able to in conditional
a If I hadn’t so much work, I __________ (fix) the fuse.
b If you had gone through the normal channels, you __________
(get) the loan.
c If he had been born in 1940, he __________ (play) with Pelé.
d If she were here, she __________ (console) him.
e If I had a screwdriver, I __________ (unscrew) this screw.
4 Examples: (permission)
She may/can/is allowed to finish work early today.
He has been allowed to do what he wants all his life.
They can/may/will be allowed to go to the disco when
they get good school results.
You may/can go skiing next week. (= I allow you to go
skiing next week.)
Next month I’ll be eighteen. Then, I’ll be allowed to
do what I wish.
He can stay up late whenever he likes.
May is formal; can, informal. Can must be used to express
general or habitual permission, as in the last example above.
Be allowed to is necessary when may or can are not possible,
ie in perfect tenses, infinitives and so on.
a You __________ stay here for a short while, but don’t be long.
b From tomorrow onwards, you (not) __________ smoke in your
c You __________ take my hand.
d We (always) __________ park in this street; but from today on,
e You __________ ask for my advice every time you need it.
‘Can/Could I go to the lavatory?’
‘Yes, you can/No, you can’t.’
‘May/Might I hold your hand?’
‘Yes, you may/No, you may not.’
Can is informal, and should be avoided in formal situations.
Could is neutral; may, the most formal. Might expresses
uncertainity; or in other words, it indicates that you are
not very sure about the answer: maybe you are hoping a
a ‘__________ I use your phone, Josephine?’
b ‘__________ I come in, please?’
‘Yes, you __________.’
c ‘__________ I bring my friends over this afternoon?’
‘No, you (not) __________. They’re terribly spoilt.’
d ‘__________ I kiss you?’
‘Yes, you __________’
e ‘__________ I sit down?’
‘Go ahead, please!’
6 Examples: (past permission)
When she was a child, she could/was allowed to watch
late-night horror movies on television.
She was allowed to watch a late-horror film on the telly
yesterday, as it was her birthday.
She could not/was not allowed to watch a late-night film,
although it was her birthday.
She could not/was not allowed to smoke at home when she
was sixteen years old.
Both could and was/were allowed to are possible for general
permission, but could is more usual. Only was/were allowed
to is used when we are talking of a particular situation.
In the negative, could not can replace was not/were not
a He (not) __________ play the music loud yesterday evening,
as her mother had suffered an attack of migraine.
b He __________ not to attend school yesterday because it was
his parents’ silver wedding anniversary.
c When she was fourteen, she (not) __________ go out with boys.
d When we were kids, we loved going to our grandparents’ place,
as we __________ stay up late.
e While she was in hospital, we __________ only see her at the
We could/would be allowed to get in if we had a permit.
(present or future)
We could have got/would have been allowed to get in if we
had had a permit. (past)
Both could and be allowed to are possible in conditional
tenses, as seen above.
a If he had got better school results, he __________ (play)
in the team.
b We __________ (hunt) here if we had a licence.
c They __________ (get) into that place if they were of age.
d You __________ (go) with us if you gave us ten pounds.
e He __________ (join) us if he hadn’t such a big mouth.
Alcoholic beverages may not be served after midnight.
We cannot/can’t take books out of this library. (Compare:
Books may not be taken out.→ a notice at a library)
May not and cannot are used to express prohibition.
May not mainly occurs in formal instructions.
a People under sixteen __________ order alcoholic drinks.
b You (not) __________ overtake. There’s a continuous line.
c You (not) __________ enter the USA without a visa.
d This room (not) __________ be used without the prior
permission of the manager.
e You (not) __________ take my bike!
9 Revision exercise.
a When I entered the house, the fuse had blown, but I
__________ see my way in the dark.
b If you taught me how to do it, I __________ do it alone.
c If you take one of these tablets, you __________ stay awake
all night long.
d You __________ overtake here. There’s a broken line.
e When you come of age, you __________ see adult films.
f If dogs __________ there, I would have taken mine with me.
g If you __________ bring your pet here, everybody would do so.
h ‘__________ I stand up, sir?’
‘No, you __________. The class isn’t over yet.’
i You (not) __________ look girls up and down like this!
j You (not) __________ come around tonight! My husband will be
k If you help me, we __________ build a shack.
l I __________ give you a hand, if you really needed one!
m I __________ play only in the park. My mom has told me not
to go outside the park.
n I’d like to __________ sing as well as you do.
o When I was your age, I __________ dance for hours and hours
without getting tired.
p She __________ win the singing contest last night. In actual
fact, she was by far the best singer.
q He had tried to speak to her many times, but without much
success. Two days ago, however, he __________ see her.
r Pets (not) __________
s You (not) __________ do such a thing here! Get out!
t You’re not going to __________ take her with you. (permission)
u Although I knew they __________ escape, I told them not to.
v ‘__________ I see Mr Wright, please?’
‘Yes, of course.’
w If you __________ meet the expenses, I’ll see to getting cheap
x ‘__________ I go topless, father?’
‘Of course you can’t!’
y If I had enough money to buy the materials needed, I
__________ put up a small cottage here. My two sons
__________ help me too. We’re very handy.
z When you finish ironing, you __________ watch the telly.
10 Examples: (present possibility)
‘Somebody has just rung the bell!’
‘It may/might/could be my sister.’
‘The bell! Can/Could it be your brother?/Do you think (that)
it is your brother?
Might and could suggest a more remote possibility than
may. In the interrogative, may is not usually possible,
and might is not very common. Instead, we use can or
could, or other alternatives (such as Do you think...).
Could implies that we are less sure about something:
Could they be pulling my leg? (I do not think they
are pulling my leg, but who knows.)
Can they be pulling my leg? (Do you think they are
pulling my leg?)
What could that be? (I found it very strange.)
What can that be? (Do you know what it is?)
a ‘Who __________ it be now?’
‘I don’t know. It __________ be my goddaughter.’
b He __________ be working in the garden. I’ll go and see if
c ‘He hasn’t come to class today!’
‘He __________ be ill in bed!’
‘Or he __________ have played truant!’
d If you tell her now, she __________ go up the wall.
e She __________ be very plain, but she’s the most incredible
person I have ever met. I think I have found my life partner.
11 Examples: (future possibility)
We may/might/could go swimming this afternoon.
He may/might/could pass his driving test.
Do you think (that) he will pass his driving test?
Is it possible/probable that he will pass his driving test?
Is it likely that he will pass his driving test?
Is he likely to pass his driving test?
Could and might indicate a smaller possibility than may.
In the interrogative, we generally use one of the alternatives
a We __________ go elsewhere this afternoon.
b They __________ travel the world next spring.
c They __________ find my fingerprints.’
‘I hope not.’
d It __________ come to nothing, but we __________ as well
try. (= We have nothing to lose by trying.)
e ‘__________ he’ll help us out until Jo recovers from her
‘I think so.’
12 Examples: (general possibility)
The outskirts of Madrid can be dangerous at times.
Can means here that it is possible for the outskirts
of Madrid to be dangerous at times. In the past, we
use could: My father could be very unfriendly, ie it
was possible for my father to be very unfriendly.
a People __________ die of a heart attack.
b This medicine __________ have side-effects.
c When you were a child, you __________ be a nuisance at times.
d Oil (not) __________ mix with water. (= It is impossible to
mix oil with water.)
e You (not) __________ wash this dress. It must be dry-cleaned.
He may/might not find the treasure island.
He cannot find the treasure island.
He could not find the treasure island.
The first sentence means that it is possible that he does not
find the treasure island; the second, that it is impossible
that he finds the treasure island. Could not carries the idea
of condition or concession: He couldn’t find the treasure
island (even if/even though he tried his best), that is, it
would be impossible for him to find the treasure island.
a You (not) __________ get the push. You’ve been working there
all your life. (= That is not possible.)
b She (not) __________ be stuck in a blizzard. It’s not snowing!
c He (not) __________ recover consciousness. The only thing we
can do now is to wait and see if he reacts to the treatment.
d We (not) __________ plant lilacs this year. (We have not
decided it yet.)
e Even if we had a key, we (not) __________ get in the house, as
the front door is jammed.
For details about the modal auxiliaries will, shall, would
and should, see units 7 and 9. For information on used to
and would, see unit 6, part 2. For information about dare,
see unit 6, part 3.
Can is possible with a future meaning when we suggest
something at the moment of speaking: We can play rugger
See unit 8, remark i.
It very often implies some kind of difficulty.
And a few other, like ‘believe’, ‘remember’ and ‘understand’.
For the usage of were in conditional clauses, see unit 24,
See unit 24.
Be allowed to is much less common than can or may. Notice
as well: I allow her to finish work early today. Be
permitted to is a very formal synonym for be allowed to.
She is permitted to finish work early today.
We permit her to finish work early today.
Be allowed to is neutral. Let is another alternative to
be allowed to, but less formal:
I’ll let her go.
I’ll allow her to go. (neutral)
I’ll permit her to go. (very formal)
Might and could are the conditional or past forms of may
and can, respectively: I told her that she might/could
go skiing the next week. See also section 14.
For conditional sentences, see unit 24.
See section 26 in this unit.
You may be my mother’s boyfriend, but this doesn’t allow
you to order me around. (= I admit that you are my
mother’s boyfriend; but, despite that, this doesn’t allow
you to order me around.)
You might be cleverer than I am, but you are very rude.
(= Although [you say that] you are cleverer than I am, you
are very rude.)
Compare these sentences:
Do you think (that) it is your brother? (Maybe the person
ringing the bell is your brother.)
Do you think (that) it will be your brother. (I think it
The burglar alarm has just gone off. Do you think (that)
someone has broken into the house? (Perhaps someone has
broken into the house.)
The burglar alarm has just gone off. Do you think (that)
someone will have broken into the house? (I do not think
it very likely.)
Could often expresses a more remote probability than might.
This depends on where we put the stress.
See the next section.
If we say that something is probable, it is more likely to
happen than if we say say that something is possible.
Could usually conveys a less likely possibility than
might. This depends where we place the stress.
Could is not possible here.
Occasionally, may could also be used instead of can:
This expression may/can also occur in a conversational
This word may/can only be used in the negative and in the
This diet may/can cause side-effects.
Nevertheless, this is not always possible. We would probably
not say The outskirts of Madrid may be dangerous at times to
express general possibility. However, in a bigger context,
it might be okay: The outskirts of Madrid may be dangerous
at times, but they are quieter than the city centre. (=
Although the outskirts of Madrid can be dangerous at times,
they are quieter than the city centre. See section 10,
The same applies to could not when it is used for permission:
You couldn’t use my car tomorrow (even if/even though you had
a driving licence). (= I would not allow you to use my car
tomorrow, or I will be using it tomorrow, so I would not lend
it to you.)
Author: Miquel Molina i Diez
Pages: 1, 2, 3 and the key
1 Negative and interrogative sentences (Page 2 and the key)
2 Short answers (Page 2 and the key)
3 Question tags (Page 2 and the key)
4 Questions and exclamations (Page 2 and the key)
5 So, neither, nor, either (the key)
6 Be, used to, would, be/get/become used to, dare, have, get, become, grow, go, turn, fall and feel (Page 2 and the key)
7 Verb tenses: forms (Page 2 and the key)
8 Irregular verbs
9 Verb tenses: uses (Page 2, Page 3, Page 4, Page 5 and the key)
10 Personal pronouns, possessives and reflexive pronouns (Page 2 and the key)
11 The genitive case (the key)
12 Singular and plural nouns (Page 2 and the key)
13 Gender (the key)
14 A, an, some, any, no, not, none, each, every and the; compounds of some, any, no and every (Page 2, Page 3 and the key)
15 Neither, not...either, none, not...any, both and all (the key)
16 A few, few, a lot, lots, a little, little, many, much, no and plenty (the key)
17 Enough, too, so and such (the key)
18 Comparative and superlative sentences (Page 2 and the key)
19 Adjective order (the key)
20 Relative clauses (Page 2 and the key)
21 Do and make (the key)
22 Modal verbs (Page 2, Page 3 and the key)
23 Infinitives, gerunds and present participles (Page 2 and the key)
24 Conditional sentences (Page 2 and the key)
25 Passive sentences (the key)
26 Reported speech (Page 2 and the key)
27 Purpose (the key)
28 Word order (the key)
29 Inversion (the key)
30 Connectors (Page 2 and the key)
31 Prepositions (Page 2, Page 3 and the key)
32 Phrasal verbs (the key)