This document discusses the meanings and uses of modal auxiliaries in English. It explains that modals have root meanings involving ability, permission, and obligation, and epistemic meanings involving possibility and necessity. Each modal has both root and epistemic uses. The document then examines individual modals such as can, may, must, and should, outlining their core meanings and how they are used to indicate ability, permission, possibility, obligation, and other concepts in different tenses and constructions. It provides many examples to illustrate the nuanced meanings and appropriate uses of each modal verb.

2. Meanings of the modals
2 main kinds of meanings for modal auxiliaries:
(I) root (or intrinsic, deontic) meaning – includes
ability, permission, obligation, volition. The root
meaning of modals involves some intrinsic human
control over events;
(II) epistemic (or extrinsic) meaning – includes
possibility, necessity, prediction. The epistemic
meaning of modals involves human judgment of
what is or is not likely to happen.

3. Meanings of the modals
Each of the modals has both root and epistemic uses. In
some instances there is an overlap of the two uses, i.e.
clauses that contain modal verbs are potentially
ambiguous:
(1) I’ll see you tomorrow then.
Will in (1) combines the meanings of volition (root
meaning) and prediction (epistemic meaning).
Normally the context makes the intended meaning clear.
There are also syntactic structures that favour root or
epistemic interpretation:
(2) (a) He must leave. = (On) mora otići. (root meaning)
(b) He must be leaving. = (On) mora da odlazi. (epistemic
meaning)

4. Meanings of the modals
There are 12 modal auxiliaries.
The set of 12 modal verbs consists of 4 paired forms
(present and past forms) and four single forms:
(I) can/could; may/might; shall/should; will/would.
(II) must, ought, need, dare.
used to, ought, dare, need are called marginal modal
auxiliaries. (see Lecture 04)

5. Meanings of the modals
Nonfinite verb phrases do not accept modal aux., but
the meanings of the modals can be added to them
through the use of semi-auxiliaries, such as have to,
be (un)able to, be allowed to, be about to:
(3) I am sorry to have to repeat this warning.
(4) Being unable to free himself, he lay beneath the
debris until rescued.
(5) The suspects admitted being about to commit a
crime.
(6) Many inmates hate not being allowed to leave the
premises.

6. Meanings of the modals
The modal verbs are also limited in their range of
time reference. When used with the present infinitive
of the main verb, they generally have a present or
future time reference.
From the point of view of meaning, past forms of the
modals (could, might, should, would) are often more
tentative or more polite variants of the present forms.
Of the 4 past tense forms, could, might and would are
used to refer to past time when followed by a present
infinitive, and then only with a restricted range of
meanings

7. Meanings of the modals
Of the 4 past tense forms, could, might and would are
used to refer to past time when followed by a present
infinitive, and then only with a restricted range of
meanings:
(7) Magda could speak three languages by the age of
six.
(8) He was very independent, and would never ask for
help.
(9) Try as he might, he couldn’t get the car to start.

8. Meanings of the modals
The use of the four past tense forms is however
automatic in sequence of tenses in reported speech:
(10) (a) “He can/could; may/might; will/would;
shall/should tell me.”
(b) I said he could; might; would; should tell me.

9. Meanings of the modals
The four single forms must, ought to, dare, need may be left
unchanged in reported speech:
(11) (a) “He mustn’t; oughtn’t to; daren’t; needn’t tell anyone.”
(b) I said he mustn’t; oughtn’t to; daren’t; needn’t tell anyone.
In (11b) (reported speech), the modal verbs do not refer to a
time earlier than the time of speaking. In the statement “You
mustn’t tell anyone”, the obligation (not to tell anyone) existed
from the time when it is expressed, i.e. from now onwards.
Similarly, in the report I said he mustn’t tell anyone, the
obligation (not to tell anyone) existed from the time when it
was expressed, i.e. from then onwards, and not at some earlier
time.

10. Meanings of the modals
The distinction between the root and epistemic meaning
of the modal verbs is important in terms of referring to the
past time in the clauses in which these modals occur.
If we wish to refer to ‘real’ past time with the modal verbs
in their root sense, we either use the past tense form of the
modal verbs (if appropriate and if available), or we use a
synonymous verb phrase (had to, didn't need to, was able
to, was permitted to, etc. If the modal verbs in their root
sense are followed by a perfect infinitive, they always
indicate ‘unreal’ past:
(12) He needn’t; should; ought to; would; might; could have
gone yesterday.

11. Meanings of the modals
If we wish to refer to ‘real’ time with the modal verbs
in their epistemic sense, we use the perfect infinitive
of the main verb. The use of the perfect infinitive of
the main verb does not usually affect the truth of the
statement, and in only a limited number of contexts
can it indicate ‘unreal’ past (i.e. contrary to past fact).
It is possible to use the present tense forms can, will,
may with the perfect infinitive to refer to past time:
(13) He must; can’t/couldn’t; will/would; may/might;
could; should/ought to have been here yesterday.

12. Meanings of the modals
(14) He must have washed the windows himself.
(14) indicates inference or logical conclusion (Mora
da je sâm oprao prozore), i.e. the epistemic
interpretation of the clause is most probable in this
context.
However, counterexamples can be found, in which
the perfect infinitive of the main verb indicates the
real past:
(15) Entrance qualifications. Candidates must have
obtained the MA or an equivalent qualification.

13. Ability or potential (can, could, be
able to)
can is used to indicate (a) the possession of ability in general
(example 16), and (b) being in a position, in particular
circumstances, to perform the activity denoted by the main verb
(example 17):
(16) He can speak German fluently. (can forms part of a
statement having general current validity)
(17) I can (or could) give him an answer now/later/tomorrow.
(can/could refer to an ability existing in certain circumstances
at the present or future time indicated)
! Important – to recognize the distinction between ability in
general and ability in specific circumstances.
! Important – both sentences (16 and 17) refer to a potential
performance of the action mentioned, not to an actual
performance.

14. Ability or potential (can, could, be
able to)
(16a) He could speak German fluently when he was younger.
(16a) represents a situation in the chronological past
parallel to that in sentence (16). It refers to the possession
of the ability to speak German, not to an actual
performance of speaking.
(17a) I could have given him an answer yesterday.
(17a) is the exact parallel in past time of sentence (17), and
means “I was in a position to give him an answer” (ability
in specific circumstances at a specific time). Again, it does
not refer to an actual performance; indeed it implies that I
did not give him an answer.

15. Ability or potential (can, could, be
able to)
If we wish to refer to an actual performance, we use a
form of be able to:
(18) I was able to give him an answer yesterday.
Verbs like see, hear, understand, etc. come into a
special category. The ability to see and the
performance of seeing are inseparable. And in this
case the use of could is possible when referring to an
actual performance in past time:
(19) (a) I can see quite clearly what you are doing.
(b) I could hear quite clearly what you were saying.

16. Ability or potential (can, could, be
able to)
The negative form couldn’t necessarily implies non-
performance of an action, and may always be used to
refer to past time:
(20) (a) He can’t speak German fluently.
(b) He couldn’t speak German fluently when I knew
him.
(21) (a) I can’t give him an answer right now.
(b) I couldn’t give him an answer yesterday.

17. Ability or potential (can, could, be
able to)
Can may be used with a future time reference (I can see
you tomorrow), but in this case the ability is more or less
taken for granted now and is not really in question. In
cases where ability will exist only eventually, or where it is
dependent on some other event in the future, we use
will/shall be able to:
(22) By the time he finishes his course, he’ll be able to speak
English well.
We also use be able to when we wish to indicate that an
action was in fact performed in the past:
(23) After looking at his notes again, he was able to
complete the exercise.

18. Ability or potential (can, could, be
able to)
Since can and could lack non-finite forms, we use be
able to where an infinitive is required or when we
want to express the perfect aspect:
(24) Ask that policeman over there. He should be able
to help you.
(25) This is all the information I’ve been able to get so
far.

19. Ability or potential (can, could, be
able to)
When could + present infinitive is used as the tentative
form of can, it has a present or future time reference:
(26) I could do it for you now if you like.
(27) I can’t do it immediately, but I could do it tomorrow
morning.
The reported version of sentence (27) is:
(27a) I told him I couldn’t do it immediately, but that I
could do it the following morning.
In conditional sentences, could often represents the unreal
present:
(28) If I knew how it worked, I could tell him what to do. (=
but I don’t know, so I can’t tell him)

20. Ability or potential (can, could, be
able to)
In a conditional sentence, could + perfect infinitive
expresses unreal past:
(29) If I had known how it worked, I could have told
him what to do. (= but I didn’t know, so I couldn’t tell
him)

21. General characteristics: can, could
Can and could are also used to refer to a general
characteristic or quality that may show itself from time to
time:
(30) A house in London can cost a lot of money.
(31) He could be very unpleasant when he was angry.
Neither of these sentences refers to an actual occurrence
of the phenomena referred to, and be able to is not used as
a substitute for can or could in such sentences.
(32) Learning a foreign language can sometimes be difficult.
= Učenje nekog stranog jezika zna ponekad biti naporno.

22. Possibility and permission: can,
could, may, might
(33) A fuller description can/may be found in the
reference books listed at the beginning of this book.
In (33), can and may are fully interchangeable. May is
a little more formal.

23. Possibility and permission: can,
could, may, might
(34) Agreement between management and unions may
be reached tomorrow.
If we wish to state a possibility rather than a fact, only
may is appropriate in (34), which means “It is possible
that agreement will be reached”.
The distinction between (33) and (34) may be
paraphrased as:
(33a) It is possible for this to be done at any time (=
statement of present fact)
(34a) It is possible that this will be done (= statement
of future possibility)

24. Possibility and permission: can,
could, may, might
Might represents the tentative form of may as used in
sentence (34):
(35) I may/might/could be wrong, of course. (present)
(36) The two parties may/might/could reach
agreement tomorrow. (future)
Could (often stressed) is quite commonly used as an
alternative to tentative might, as in (35) and (36).

25. Possibility and permission: can,
could, may, might
However, could is not used in this way in affirmative
negative sentences:
(37) They may/might not reach agreement tomorrow.
(38) They could not reach agreement tomorrow.
These sentences have quite different meanings. The
reason for this lies in the way the negative particle not
operates. In affirmative sentences with may or might (in
the sense of possibility), not goes with the main verb:
(39) They may/might not reach agreement tomorrow. = It is
possible that they will NOT reach agreement tomorrow.

26. Possibility and permission: can,
could, may, might
With could, not goes with the modal (unless we use a
very special stress and intonation pattern):
(40) They could not reach agreement tomorrow. = It is
NOT possible that they will reach agreement.

27. Possibility and permission: can,
could, may, might
To refer to past time, we use may, might and could
with a perfect infinitive:
(41) No statement was issued after yesterday’s talks,
but it is thought that the two parties may have reached
agreement. (= It is possible that they reached
agreement)
Might and could suggest that the possibility is a little
more remote:
(42) The two parties might/could have reached
agreement.

28. Possibility and permission: can,
could, may, might
Giving permission, we use can or may. May is
considered more formal:
(43) You can/may speak to the patient for just a few
minutes now/later/tomorrow.
Asking for permission, we use can or may. Asking
tentatively (more politely), we use could or might:
(44) Can/may; could/might I speak to you for a
moment?

29. Possibility and permission: can,
could, may, might
In the reported version of sentence (43), we use could or might:
(44) The nurse said we could/might speak to the patient for just a
few minutes.
We do not use could/might + perfect infinitive to refer to
permission given in past time. We are obliged to use a
paraphrase:
(45) We had (or were given) permission to speak to the patient.
Could/might + perfect infinitive suggest that permission existed
but wasn’t acted on, perhaps because of ignorance on the part
of the subject:
(46) You could/might have come yesterday e.g. if you had wanted
to.

30. Concessive meaning of may
(47) Your job may be very demanding, but at least it
isn’t boring. = Although your job is very demanding,
at least it isn’t boring.
May + perfect infinitive is used to refer to past time:
(48) The work may have been difficult, but at least it
was interesting.

31. Tentative way of making a request,
suggestion or recommendation:
might
(49) You might send me a postcard while you’re on
holiday.

32. Sarcasm or annoyance on the part
of the speaker: might
(50) You might look where you’re going!
(51) You might have told me you weren’t coming!