Can is used to talk about ability, possibility, permission, and requests. It is followed by an infinitive without "to" and there is no "s" in the third person singular. Can is used to talk about present or general ability, theoretical possibility, and logical possibility in questions or negatives. It is also used to ask for and give permission and to make polite requests or offers. Could is sometimes used as a more polite form of can when asking for permission or making requests.

1. © Rafael Moreno Esteban 2007© Rafael Moreno Esteban 2007
Can / Can’tCan / Can’t
CanCan is used to talk aboutis used to talk about
ability and possibility, to askability and possibility, to ask
for and give permission, andfor and give permission, and
to make requests and offers.to make requests and offers.

2. © Rafael Moreno Esteban 2007
CanCan is a modal auxiliary verb. It is followed by anis a modal auxiliary verb. It is followed by an
infinitive without to.infinitive without to.
There is noThere is no –s–s in the third person singular.in the third person singular.
 I can swim. (=knowI can swim. (=know
how to)how to)
 She can sing. (NOTShe can sing. (NOT
She cans …)She cans …)
 HeHe can runcan run a mile ina mile in
four minutes. (four minutes. (NOTNOT
He can to run…)He can to run…)
 SheShe can playcan play tennistennis
very well. (very well. (NOTNOT SheShe
can to play tennis…)can to play tennis…)
Questions and negativesQuestions and negatives
are made withoutare made without do:do:
 CanCan you speakyou speak
French? (French? (NOTNOT Do youDo you
can speak French?)can speak French?)
 II can'tcan't swim. (swim. (NOTNOT II
don't can swim.)don't can swim.)
 YouYou cannotcannot fool him.fool him.
((NOTNOT You don't canYou don't can
fool him.)fool him.)

3. © Rafael Moreno Esteban 2007
Pronunciation notesPronunciation notes
 There are two main pronunciation problemsThere are two main pronunciation problems
related torelated to can/can’tcan/can’t
 CanCan is usually unstressed /kis usually unstressed /kn/ in + sentencesn/ in + sentences
likelike I can singI can sing..
 The negativeThe negative can’tcan’t is always stressed. Notis always stressed. Not
stressing it can cause a communication problemstressing it can cause a communication problem
(the listener may understand(the listener may understand cancan NOTNOT can’tcan’t). The). The
pronunciation of this word varies among differentpronunciation of this word varies among different
groups of native English speakers, from /kgroups of native English speakers, from /knt/ tont/ to
/k/knt/, The important thing is that we stress itnt/, The important thing is that we stress it
quite strongly.quite strongly.
 Examples:Examples: You can tell them. / You can’t tellYou can tell them. / You can’t tell
them.them.
 We only stressWe only stress cancan in short answers:in short answers: YesYes, I, I cancan..

4. © Rafael Moreno Esteban 2007
To talk about theoreticalTo talk about theoretical
possibilitypossibility
 We can useWe can use cancan to talk aboutto talk about
‘theoretical’ possibility – to‘theoretical’ possibility – to
say that situations and eventssay that situations and events
are possible theoretically.are possible theoretically.
 GlassGlass can becan be blown. (It isblown. (It is
theoretically possible to blowtheoretically possible to blow
glass.)glass.)
 WarsWars can break outcan break out anyany
time. (It is theoreticallytime. (It is theoretically
possible for wars to break outpossible for wars to break out
any time.)any time.)
 SmokingSmoking can causecan cause cancer.cancer.
 NoiseNoise can becan be quite a problemquite a problem
when you are living in a city.when you are living in a city.
Note that we do not useNote that we do not use cancan to talkto talk
about future probability – to sayabout future probability – to say
that something will happen inthat something will happen in
future. We express this idea withfuture. We express this idea with
maymay oror might.might.
 It may rain this evening.It may rain this evening. (NOT It(NOT It
can rain …)can rain …)
 There may be a strike next week.There may be a strike next week.
(NOT There can be a strike …)(NOT There can be a strike …)
 I may get a job soon.I may get a job soon.
Note thatNote that mightmight expresses a lessexpresses a less
definite possibility thandefinite possibility than maymay..
CouldCould is also used in the sameis also used in the same
sense.sense.
 It could rain this evening. (= ItIt could rain this evening. (= It
might rain this evening.)might rain this evening.)

5. © Rafael Moreno Esteban 2007
To talk about logical possibilityTo talk about logical possibility
 CanCan is often used in questions andis often used in questions and
negatives to talk about the logicalnegatives to talk about the logical
possibility that something is true.possibility that something is true.
 Example:Example: There is the doorbell. Who can itThere is the doorbell. Who can it
be?be?
 With this meaningWith this meaning cancan is not possible inis not possible in
affirmative clauses. Instead, we useaffirmative clauses. Instead, we use
could, maycould, may oror might.might.
 Example:Example: Where is John? HeWhere is John? He
could/may/might be in the garden.could/may/might be in the garden. (NOT(NOT
He can be in the garden.)He can be in the garden.)

6. © Rafael Moreno Esteban 2007
To talk about abilityTo talk about ability
We can useWe can use cancan to talk aboutto talk about
present or general ability – topresent or general ability – to
say that we are capable ofsay that we are capable of
doing something.doing something.
 II can speakcan speak 10 languages.10 languages.
 SheShe can cookcan cook well.well.
 Can you knit?Can you knit?
 I can drive a bus.I can drive a bus.
Note thatNote that be able tobe able to can oftencan often
be used with similarbe used with similar
meanings.meanings.
 He is able to support her.He is able to support her.
(= He can support her.)(= He can support her.)
 They were able to catch theThey were able to catch the
thief. (= They could catch thethief. (= They could catch the
thief.)thief.)
CannotCannot (also can’t) shows(also can’t) shows
inability.inability.
 II can speakcan speak French, but IFrench, but I
cannot writecannot write it.it.
 Most peopleMost people cannot readcannot read
traffic signals.traffic signals.
 II can'tcan't drive.drive.
 We do not useWe do not use cancan to talkto talk
about future ability. Instead,about future ability. Instead,
we usewe use will be able towill be able to oror
other words.other words.
 Someday scientistsSomeday scientists will bewill be
able toable to find a cure for cancer.find a cure for cancer.
((NOTNOT Someday scientists willSomeday scientists will
can find a cure for cancer.)can find a cure for cancer.)

7. © Rafael Moreno Esteban 2007
To ask for or give permissionTo ask for or give permission
CanCan is sometimes used tois sometimes used to
ask for and giveask for and give
permission. Some people,permission. Some people,
however, think thathowever, think that maymay isis
more correct thanmore correct than can.can.
 CanCan I use your car, John?I use your car, John?
 CanCan we park over there?we park over there?
 You canYou can go out and playgo out and play
after you have finishedafter you have finished
your homework.your homework.
 YouYou cancan park on eitherpark on either
side of the road here.side of the road here.
 CanCan I go to the movies,I go to the movies,
mom?mom?
Note that we can also useNote that we can also use couldcould
to ask for permission. It is ato ask for permission. It is a
more polite form ofmore polite form of can.can.
 CouldCould I speak to Mr. John,I speak to Mr. John,
please?please?
 CouldCould I have look at yourI have look at your
newspaper?newspaper?
 CannotCannot is used to refuseis used to refuse
permission.permission.
 Can I go to the movies, mom?Can I go to the movies, mom?
No, you can’t.No, you can’t.

8. © Rafael Moreno Esteban 2007
To make requests and offersTo make requests and offers
CanCan is used in polite requests and offers ofis used in polite requests and offers of
help.help.
 CanCan you turn that music down? I am tryingyou turn that music down? I am trying
to work.to work.
 CanCan you get me a cup of coffee?you get me a cup of coffee?
 CanCan I help you with those bags?I help you with those bags?
Note thatNote that CouldCould is a more polite way ofis a more polite way of
making requests and offers.making requests and offers.
 CouldCould you help me with my homework?you help me with my homework?
 CouldCould you lend me some money?you lend me some money?

9. © Rafael Moreno Esteban 2007
ExercisesExercises
Complete with a suitableComplete with a suitable
word:word:
 11 I ______ go out tonight.I ______ go out tonight.
I'm busy.I'm busy.
 22 Can you ______ to theCan you ______ to the
cinema tonight?cinema tonight?
 33 You ______ park here. It'sYou ______ park here. It's
no parking.no parking.
 44 ______ you tell me the______ you tell me the
time, please?time, please?
 55 She can ______ EnglishShe can ______ English
well.well.
 66 I ______ play football, butI ______ play football, but
not basketballnot basketball
Complete the sentencesComplete the sentences
withwith cancan oror can'tcan't..
 11 ______ I park my car______ I park my car
here?here?
 22 Where? I ______ seeWhere? I ______ see
him.him.
 33 ______ you help me______ you help me
with my homework?with my homework?
 44 You ______ smokeYou ______ smoke
there, but not here.there, but not here.
 55 Sorry. I ______Sorry. I ______
remember the answer.remember the answer.
 66 I ______ speak SpanishI ______ speak Spanish
and Italian.and Italian.

10. © Rafael Moreno Esteban 2007
ExercisesExercises
Complete with a suitableComplete with a suitable
word:word:
 11 I ______ go out tonight.I ______ go out tonight.
I'm busy.I'm busy.
 22 Can you ______ to theCan you ______ to the
cinema tonight?cinema tonight?
 33 You ______ park here. It'sYou ______ park here. It's
no parking.no parking.
 44 ______ you tell me the______ you tell me the
time, please?time, please?
 55 She can ______ EnglishShe can ______ English
well.well.
 66 I ______ play football, butI ______ play football, but
not basketballnot basketball
Complete the sentencesComplete the sentences
withwith cancan oror can'tcan't..
 11 ______ I park my car______ I park my car
here?here?
 22 Where? I ______ seeWhere? I ______ see
him.him.
 33 ______ you help me______ you help me
with my homework?with my homework?
 44 You ______ smokeYou ______ smoke
there, but not here.there, but not here.
 55 Sorry. I ______Sorry. I ______
remember the answer.remember the answer.
 66 I ______ speak SpanishI ______ speak Spanish
and Italian.and Italian.