Verbs: Modal Auxiliaries - Single-Worded and Phrasal Types

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These auxiliary verbs are characteristically used with a verb of predication and express a modal modification. They differ formally from other verbs in English, lacking "-s" and "-ing" forms.
Modal auxiliaries are auxiliary verbs that lend different shades of meaning to the main verb to
which they are attached. Modals help to express the mood or attitude of the speaker and
convey ideas about possibility, probability, necessity, obligation, advisability, and permission.
The single-word modal auxiliaries are:
Can May Must Shall will
Could Might Should Would
Some phrasal modal auxiliaries are:
Be able to Be supposedto Have to Ought to Have better
Be going to Be to Have got to Used to
Single-word modal auxiliaries are always followed by the simple (or stem”) form of the verb.
Here are some examples of the how single-word modal auxiliaries influence meaning:
Statement Meaning
Ican go. o> Iam able to go. / | have pemnission to go.
| could go. — If certain conditions were met, | would be able to go.
Imay go. =§ [> t's not certain, but there's a chance that I'll go. /| have
pemiission to go.
Imight go. => t's not certain, but there's a chance I'l go.
Imust go. ©§. [==> Iam obliged to go.
Ishall go. =—§ [==> Iam going (in the future).
should go. [===> tts advisable /recommended/obligatory that | go.
| will go. > II's certain that | am going (in the future). / am wiling to go.
I would go. (===>) my going is uncertain; it depends on certain conditions.
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2. The following chart demonstrates some uses for single-word modal auxiliaries. Notice that in
some cases when the verb tense changes, the modal is replaced with another word or group of
words. Empty spaces denote non-existent forms.

ery ey ed Sie ina eens
can |1.Abilty He can play the piano. |He could play the He willbe able to play |He cannot play the
piano. the piano, piano.
2. Opportunity can go now that ve [Iwas able fo gowhen! |leangowhen finish |! cannot go.
finished working, finished working, ‘working later tonight.
3. Permission Their parents say they |Theirparents said they | Theirparents will surely |They cannot have a
can haves party. | were allowed to havea | say that they ean have | party
party party
4. Informal request Can! borowyour | Cant borow your
(refersto near future) book? book?
5. Possibility ttean be fiting to study Itean't be tiring to sit
(usally o ‘and work at the same ‘round and watch TV
generalization) time. all day!
Could |1.Past of can Before | hurt my wrist | Even before | hurt my
could toss pizza dough. ‘wrist, Coukdn’t toss
pizza dough.
2. Conditional leoukd have made an |Icould make an | couldnt make an
omelet ifwe had had | omeletif we have the | omelet evenif we had
the ingredients ingredients the ingredients.
3. Suggestion You could have taken a | You could take along
long weekend to visit | weekend to visit your
jyour family farnly.
4-Polte Request ‘Could you phoneme | Couldn't you phone me
(refersto near future) when you anive? when you artive?
5. Possibility / ‘Ms.Stevens could be |Ms. Stevens could have |Ms.Sievens could | Ms. Stevens couldn'tbe
Impossibility the electors’ choice for|been the electors’ | become mayor the electors choice for
mayor. choice for mayor mayor.
way —_|1.Permission Youmay submit your |Youwere allowedto | When youfirish. you | You may not submit
paper via email now. | submit your papervia_| may submit your paper | your paper via emall
email via email
2.Polte Request ‘May | use your phone?
(refers to near future)
3. Possibility The bakey maybe |The bakery may have |The bakery may open |The bakery may not
open now, opened eatiertoday. _| later today. open.
might [1 Request (fers to Might | use your
near future) phone?
2. Conditional Ifyou give me a Ifyou had given mea |ifyouwil gvemea | Evenif yougive me a
chance, | might ‘chance,|mighthave | chance, | might chance, | might not
impress youl impressed you! impress you! impress you.
3. Suggestion You might have called | You might call to say | You mightnot want to
tosayyouweren't | you aren't coming. _ | callto say you aren't
‘coming, coming.
4. Possibility ‘My dog might be the |My dog mighthave [My dog might make a. | My dog might not make
‘one who made the | made the mess. mess ames.

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must |. Certainty She must be the best | She must have been the She must not be the
‘athlete in ourschool’s | best athiete in our best athlete in our
history schoo''s history schoo’ histor
2 Strong Tobe healthy, youmust |To have stayed healthy, [To be healthier you [To be healthy, you
recommendation | eatwel. you should have eaten |should eat better. | musint eat poorly
3. Necessity Vaitorsmustsign in at | Inthe past, visitors had fo [in the future, visitors | Vaitors don't have fo
reception signinat reception. | mustsign inat signin at reception,
(Must not | 4 Prohibition You must not dizupt his
Shalt _| 1. Inevitabilty ‘One day,we shall | Humanity shall never
‘overcome our ‘abandon the quest for
dependence onci. | immortality
2. Promising Ishall ensure that | shall not et you down.
(Bish usage) everything goes
‘according fo plan.
3. Future Action ‘Ourirain shail arive | Our train shall not arive
(Bish usage) ahead of schedule. | chead of schedule
after al

Should | 1.Recommendation |For stong bones, you —_| For stronger bones, you _| For strong bones, you _| You shouldn't drink too

should drink milk, should have drunk milk. | should start drinking | much mik.
2. Obligation | should return this
library book.
3. Expectation She shouldbe at the | She should have arived | She should arrive at the | She shouldn't be at the
‘itpatt right now. ‘at the airport by now. | airport before 9 o'clock | apart yet.
wil ]1. Future Action We will go fo the movie | We will not go to the
tonight. movie tonight.
2. Promising | will ensure that | will not disappoint you.
‘everything goes
‘according to plan.

Would |1. Past of will You said we would go to You said we wouldn't
the movie. go.
2. Conditional IFlwere in trouble, | would | | had been in trouble, |_| If got into trouble,|__ | Evenif | got into trouble,
‘ask him for help. would have asked him for | would ask him for help. || would not ask him for
help. help.
3. Repetition in When we were kids, we When we were kids, we
the past / would aways play street would not play street
habitual action
or behaviour hockey in the alley. hockey in the alley.

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Like single-word modal auxiliaries, phrasal modals are always followed by the simple (or “stem”)
form of the vert.
Unlike single-word modals, however, most phrasal modals contain the verbs be or have, which
must be conjugated to identify tense and number (| am, you are, he/she/itis,| was, you were,
he/she/it was, etc). Exceptions are used fo and ought fo, which require no change in verb form.
Had better is never conjugated, and it does not include the word fo as the other phrasal modals
do. Like single-word modal, itis followed immediately by the simple form of the vert.
Here are some examples of how phrasal modal auxiliaries influence meaning:
Statement Meaning
lam able to go. c— _Icango./ Ihave pemnission to go.
lam going to go. > _ iwilbe going (in the future).
lam supposed to go. [==> tis understood/expected/agreed-upon that | will go.
lam to go. > am expected/obliged to go. / Ihave been ordered
Ihave to go. o> lamobiiged to go.
Ihave got to go. > _ 1am obliged to go (extra emphasis on the obligation).
lought to go. > ttisrecommended/advisable that | go.
lused to go. > went on aregular basis (habitual action in the past).
Ihad better go. > tris advisable that | go.
Copyright Marianopolis College. Used with permission.
5. The following chart demonstrates some uses for phrasal modal auxiliaries. Notice that in some
cases when the verb tense changes. part of the modal is replaced with another word or group
of words. Empty spaces denote non-existent forms.

ren es Se eT fone ead
Be able to | Abily She is able tojcin us. | She was able fo join us. | She will be able fo join |She is not able to join
us. us
Be going 10 | Plan (for the future) Iwas going io siat [lam going tosiat —_|l am not going to
university next fall
university next fal
start university next

Be supposed to | Expectation He was supposedio | He is supposed fo bring |He is not supposed fo
bring dessert, but! __| dessert tonight. bing anything
‘guess he forgot. tonight!
Beto | Expectation / She was fo see the [She isto see the She is not fo see the
obligation project through tots | project though toits | project though toits
end, but she left befare Jend,no matterhow [end after al
its completion. long it takes
Have to | Obigaton Ihave foleavenow. |ihadioleave then. | Ihave foleavein | donot have fo
(= mus) ‘approximately 10 leave.
Have gotta |Sirongabigaion || have gotfo prepare | Ineeded fo prepare my |Ihave got fo prepare || do not need fo
mypresentationnow. |presentation at that | mypresentationas | prepare my
time. soonas Ifinish dinner. | presentation
Janymore. I'm ready!
‘Oughtto | 1Recommendation [One ought foexpress | We should have seni a |We ought fosenda | We ought not forget.
one’s gratitude note to ourhostess. | hank you note to our |*tois dropped in the
hostess. negative
2. Certainty When one studies | With all the studying she | With all the studying
hard, one oughtfo —_|did, she ought fo have_| she’s done, she ought
pass passed her exam, fo pass her exam.
Used to | Habitual past action / ‘My grandfather used fo
behaviour walk 3 miles to and
from school every day!
Hadbetter [Recommendation You had better go. i's |You had better not

getting late!
go. The weather
looks pretty nasty!

For more information on modals and other auxiliary verbs, please refer to the following websites:
You are also welcome to make an appointment with The Leaming Centre staff:
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