1. CAN AND CAN´T AND
OTHER MODALS USED TO
POSSIBILITY
EXPRESS
AND ABILITY

2. ABILITY
• When we talk about ability, we mean two things.
First, we mean general ability. This is something
that once you have learned you can do any time
you want, like being able to read or swim or speak
a language, for example.
The other kind of ability is specific ability. This
mean something that you can or can't do in one
particiular situation. For example, being able to
lift something heavy, or find somewhere you are
looking for.

3. Present: can / can’t (for both
general and specific ability)
• I can play the piano.
• She can speak English.
• He can’t drive – he’s too tired.
• We can’t come now.
• We use 'can' and 'could' to talk about a skill or
ability.

4. • We use 'can' and 'could' to talk about a skill or
ability.
• For example:
• She can speak six languages.
• My grandfather could play golf very well
• I can't drive

5. Past: could / couldn’t (for
general ability)
• I could read when I was four.
• She could speak French when she was a child,
but now she has forgotten it.
• He couldn’t dance at all until he took lessons.
• My grandfather couldn’t swim.

6. was able to / couldn’t (for
specific ability)
• When the computer crashed yesterday, I was
able to fix it.(not ‘I could fix it’)
• She was able to pass the exam, even though
she hadn’t studied much.(not ‘she could pass’)
• He called us because he couldn’t find the
house.
• I couldn’t open the window.

7. could + have + past participle (an
ability someone had in the past,
but didn’t use)
• I could have played the piano well but I didn’t
practice enough.
• We could have come earlier.
• She could have studied law, but she preferred
to become a secretary.

8. Future: will / won’t be able to
(general ability)
• At the end of the course, you will be able to
make your own website.
• He won’t be able to speak Japanese in a week!
It will take months.

9. can / can't (specific ability)
• I can help you tomorrow
• I can't come to the party

10. Modal Verbs of Ability
• The modal verbs of ability show just that --
ability.
• Ability can be expressed in the past, present,
or future. It can be an ability that was used
over and over again, or something that was
done just once, on a special, or rare, occasion.

11. • The modal verbs of ability are can, could, and be able to.
Can is used to talk about ability in the present or future.
He can read well.
Could is used to talk about ability in the past.
He could read well when he was younger.
Be able to is used to talk about a certain, or particular,
ability.
He was able to read when he was 4 years old.
** While could might be used in the last example, be able
to emphasizes the early age at which he could read.
Could have, followed by a past participle indicates an
ability NOT used and often shows disapproval.
He could have called me! (He didn't)
Could not have followed by a past participle indicates that
an ability didn't exist in the past.

12. • I couldn't have phoned you yesterday,
because I lost my phone last week.
Be able to is used with other modals or when
forming the 'ing' or 'to' infinitive forms.
You will have the satisfaction of being able
to read my report.
Nobody will be able to read what you have
written.
We use can or could with the senses verbs; see,
hear, smell, etc., to say that someone is aware of
something through their senses.
I can smell gas downstairs.
I could see a few stars in the sky last night.
I couldn't hear what she said because of the
noise.

13. MODAL VERBS: POSSIBILITY
The modals of possibility (may, might, can,
could) mean something like: "The way I
see/feel things in the present circumstances, it
is possible that. For may and might, we should
add: (..if I have anything to do with it).
Could and might express remoteness of any
kind (past time, unlikely occurrence, stiffness -
due to shyness or respect-.

14. • May and might express a more personal
involvement in the creation of the possibility
(an extrictly personal opinion, or some kind of
authority.

15. There are many kinds of
possibility:
• Probability, chances: This could be your lucky
day (It is likely, possible that..)
• Theoretical possibility, options: We can be
friends, if you want to.
• Ability: He can dance on his nose (He is able to..)
• Assumptions (logical possibility): This may well
be the purse you lost
• Permission: Can I go to the cinema? –No, you
may not. (You’re not allowed to..)

16. Ability and Possibility
•
•
Explanation
Can is often used to express ability and possibility. Look at the
following examples:
Ability: Jim can sing well.
Possibility: We can clean our apartment tomorrow.
Negative forms: cannot or can not; contraction-->can't
Andy can't come to class tomorrow.
Past ability and possibility: could and could not; contraction--
>couldn't
When Tom was little, he could speak English and Spanish.
Jerry couldn't come to work yesterday because he was sick.

17. • Question forms and short answers:
Can Gary play the piano too? Yes, he can.
Can animals reason like humans? No, they
can't.