This document defines and categorizes modal auxiliary verbs. It begins by defining modal verbs as verbs that accompany other verbs and add meanings like obligation or permission. It then lists common modal verbs and groups them based on whether they express a single or double meaning. The document explains the structure of modal verbs and how they are used in different tenses and forms. It categorizes modal verbs based on the meanings they express, such as ability, obligation, possibility, and certainty. It concludes by explaining how modal verbs are used with perfect infinitives to discuss past possibility, certainty, or advice.

1. MODAL AUXILIARY VERBS
By JESÚS HERRERO

2. MODAL AUXILIARY VERBS
DEFINITION
LIST
 STRUCTURE
 GROUPS
 PERFECT MODALS


3. DEFINITION

4. MODAL AUXILIARY VERBS
DEFINITION
1. They are part of the verbal phrase:
I mustmust there before 7 o'clock.
get get
2. They always accompany, assist or help
other verbs.
3. They add abstract (modal) meanings like
obligation, permission, advice, etc

5. LIST OF MODAL VERBS

6. LIST OF MODAL VERBS
can
could
*be able to
must
*have to
need
should
may
*ought to
might

7. MODAL VERBS STRUCTURE

8. MODAL VERBS STRUCTURE
1. How do we use modal verbs?
Affirmative: subject + modal + infinitive
ex. She should stay
Negative: subject + modal(n't) + infinitive
ex: She shouldn't stay
Interrogative: (Wh)Modal + subject + inf.?
ex: Why should she stay?

9. MODAL VERBS STRUCTURE
2. Modal verbs are used with infinitives without
to (bare infinitives) with the exception of
ought to:
We must get there before 7 o'clock.
She should study harder.
I ought to go home now.
(Have to is studied with modal verbs but it's not
a pure modal verb as it needs auxiliary verbs
and has -s in the third person singular)

10. MODAL VERBS STRUCTURE
3. Modal verbs do not add -s or -es to the third
person singular. They are invariable verbs.
He can swim.
He cans wim

11. MODAL VERBS STRUCTURE
4. They don't need auxiliaries to form short
answers or negative and interrogative
sentences:
She shouldn't eat salt.
She doesn't should eat salt
May I help you? Yes, you may.
Do I may help you? Yes you do
5. They do not have infinitives or -ing forms.
canning
to might

12. MODAL VERBS STRUCTURE
6. Modal verbs do not have all the tenses.
They use other verbs to complete the
tenses:
can > could, be able to
They can swim now > She will be
able to swim next year
must > had to
You must come early > You had to
come early yesterday

13. GROUPS OF MODAL VERBS

14. GROUPS OF MODAL VERBS
We are going to study them from two points of
view:
a. number of meanings or concepts that
they express:
single, double
b. modal meanings that they express:
permission, ability, obligation ...

15. NUMBER OF MEANINGS

16. GROUPS OF MODAL VERBS
(a. number of meanings)
1. The same modal verb can have different
meanings depending on the context.
May I come in? It may rain tomorrow
2. We can make two categories:
a. Single concept modals: These modal
verbs have 1 meaning
b. Double concept modals: They have 2
meanings

17. GROUPS OF MODAL VERBS
(a. number of meanings)
Single concept Double concept
Will
Might
Should
May
Must
Would
Can
Could

18. GROUPS OF MODAL VERBS
(a. number of meanings)
Single concept modals
Modal Concept
Will
Future
Might Probability
Should
Advice
Example
Peter will visit London some day
He might see Big Ben
He should wear comfortable shoes

19. GROUPS OF MODAL VERBS
(a. number of meanings)
Double concept modal
Modal
May
Must
Would
Concept
Permission
Probability
Obligation
Certainty
Conditional
Example
May I come in?
I may go to London next summer
Students must wear uniforms
They must be at home, the lights are on
I would visit London if I had enough money
Habitual past action
When I was a child I would go swimming every day

20. GROUPS OF MODAL VERBS
(a. number of meanings)
Double concept modal
Modal
Could
Can
Can't
Concept
probability
Past ability
Permission
Ability
Impossible
Example
That could be him. He said he'd phone
I could play the trumpet when I was 10
Students can wear T-shirts
They can swim, they did a course last summer
They can't be at home, they left yesterday
No permission
They can't be at home, it's not their house

21. MODAL MEANINGS

22. GROUPS OF MODAL VERBS
(b. modal meanings)
Modal verbs express a series of modal
meanings like:
- ability
- obligation
- prohibition
- necessity
- advice
- possibility
- certainty

23. GROUPS OF MODAL VERBS
(b. modal meanings)
ABILITY
(can, could, be able to)
1. Present: can
saben
Two of my friends can play the guitar.
2. Past: could
sabía
When he was a child he could ski well.

24. GROUPS OF MODAL VERBS
(b. modal meanings)
ABILITY
podrán
hemos podido
3. Other tenses: be able to
- Next week they'll be able to vote.
(future)
- We haven't been able to go on holiday this
year. (present perfect)
- We would be able to do it. (conditional)
podríamos

25. GROUPS OF MODAL VERBS
(b. modal meanings)
OBLIGATION
Tienen que
Present: must
Applicants must answer the questions
honestly
Tengo que
Tendré que
He tenido que
Other tenses (including present): have to
- I have to study hard this year
- I will have to work hard as a lawyer
- I have had to stay at home lately

26. GROUPS OF MODAL VERBS
(b. modal meanings)
PROHIBITION
We use mustn't to express prohibition
- You mustn't eat too many sweets
- You mustn't cheat in exams
No debes / no puedes

27. GROUPS OF MODAL VERBS
(b. modal meanings)
NECESSITY / NO NECESSITY
Hay que, es necesario que
Affirmative: need to (it's not a modal verb)
You need to do this to pass the subject
Negative: needn't (no obligation) = don't have to
You needn't do it = You don't have to do it
Interrogative: need
Need I do this?
No es necesario

28. GROUPS OF MODAL VERBS
(b. modal meanings)
ADVICE
deberían
You can use ought to, should, shouldn't to
express advice or recommendation.
- Candidates should be friendly
- You shouldn't worry too much about
exams
No deberías
- Candidates ought to be friendly

29. GROUPS OF MODAL VERBS
(b. modal meanings)
POSSIBILITY
Puede que, tal vez
Present & future: may, may not, might,
mightn't, could:
- It may be time for Linda to go
- They might choose Danny
- They could be on the train
Past: may / might / could + have + past perfect
He might have received our message

30. GROUPS OF MODAL VERBS
(b. modal meanings)
CERTAINTY / LOGICAL DEDUCTION
Debe de
Positive: must
It must be quite late, because it's getting
dark
Negative: can't
That can't be true
No puede

31. MODALS + PERFECT
INFINITIVES

32. MODALS + PERFECT
INFINITIVES
When they refer to the past, certain meanings
must be expressed with a modal + perfect
infinitive (have + past participle):
1. certainty / logical deduction
positive, negative
2. possibility
3. advice / recommendation

33. MODALS + PERFECT
INFINITIVES
1. CERTAINTY / LOGICAL DEDUCTION
Positive: must have + past participle
Debió de (haberse)
Danny must have felt disappointed when he
didn't win the prize
No pudo (haber)
Negative: can't have + past participle
She can't have passed the exam, she
didn't study at all

34. MODALS + PERFECT
INFINITIVES
2. POSSIBILITY
When we talk about possibility about the past
we can use: might / may / could + have +
past participle:
-They might not have received our
message
- He may have gone to the cinema
- The government could have acted more
quickly
Podría haber / no haber
Puede que haya / no haya

35. MODALS + PERFECT
INFINITIVES
3. ADVICE / RECOMMENDATION
When we express criticism or regret about a
past action we can use should / shouldn't
- Linda shouldn't have talked so much
- We should have gone to see that film
while it was still on at the cinema
No debería haber / debería haber

36. PRACTICE
Click on this link to practice modal verbs:
http://mimosa.pntic.mec.es/~jherre23/