Modal Verbs Universe

the modal/ semi-modal verbs

UniversE

A world of infinite possibilities!

THE MULTIPLE MEANINGS galaxy

solar systeM: ability

Ability: having the skill and power to do something

planets AND STAR of ABILITY

BE ABLE TO STAR

COULD / COULDN'T

CAN / CAN'T

(Both general and specific) Ability in the present, past, future It can be used with other modal verbs e.g. I might be able to see you tonight.

General ability in the past

General ability in the present

could or was/were able to?

How to tell which one to use!

To talk about what we were generally able to do in the past. We use it to talk about past actions we did again and again! e.g. I could run really fast when I was young.

We mostly use "was/were able to" to talk about a single action in the past, usually something difficult we managed to do once or twice. e.g. I was able to reach the top of the mountain once!

could

be able to

solar systeM: rp

R: Request P: Permission

planets and stars of rp

BE ALLOWED TO STAR

BE PERMITTED TO STAR

CAN / CAN'T

FRIENDLY/INFORMAL Can I go out?Can you help me?ALSO! Will you...

COULD / COULDN'T

MAY/MIGHT

MORE POLITE Could I go out, please? Could you help me? ALSO! Could you...

A LOT MORE POLITE/ FORMAL May I go out, please?

solar systeM: prohibition

Prohibition = saying that something is officially not allowed

one big planet!

The planet of Prohibition: MUST NOT (MUSTN'T)

We can however use other modal verbs and expressions to show that something isn't allowed. These are the following: may not can't aren't allowed / aren't permitted to ARE/IS TO In the past: couldn't, wasn't /weren't allowed/permitted to, wasn't/weren't to

THE obligation galaxy

Obligation: Something that you must do according to rules or laws

planets of obligation

HAVE TO

NEED / NEED TO

MUST

Obligation/ Necessity in the past, present and future

Necessity in the past, present and future

Obligation/Duty in the present / future

must or have to?

When do we use each?

HAVE TO

MUST

We use HAVE TO when someone else believes that something is important or necessary to do. e.g. Doctors have to wear uniforms at work.

We use MUST when WE believe that something is important or necessary to do. e.g. I must see my friends.

VS

important note!

MUSTN'T / DON'T HAVE TO

MUSTN'T shows PROHIBITION, that something is not allowed to do DON'T HAVE TO/DON'T NEED TO/NEEDN'T show LACK OF NECESSITY, that is that something is not necessary to do

THE deduction galaxy

Deduction: the process of deciding that something is true using the available information

planets of DEDUCtion

CAN'T

MAY/MIGHT

MUST

100 % Certain something ISN'T true in the present/future

70% Certain something is true in the present/future

100% Certain something is true in the present/future

THE possibility galaxy

3 planets / 3 levels

COULD

MAY

MIGHT

Ben isn't here - he could still have a problem with his knee.

Ben isn't here - he may still have a problem with his knee.

Ben isn't here - he might still have a problem with his knee.

THE ADVICE galaxy

planets of ADVICE

OUGHT TO / OUGHTN'T TO

HAD BETTER

SHOULD/SHOULDN'T

Should can also be used for expectations (what will most likely happen)! e.g. You're running one mile? That should be difficult!

is that all?

What do you think the sentences below mean?

Compare: could have done sth

I would have come to the party, but I broke my leg.

He was at work at the time so he can't have stolen the money.

Her eyes were red - she must have been crying.

I can't find my book - I might have left it at my friend's house.

You got C - in the test. You should have studied harder.

Oh, thanks for the gift, but you needn't have bought it.

MODAL PERFECTS

Modal forms expressing past meanings REMEMBER! MODAL VERB + HAVE+ VERB'S PAST PARTICIPLE

Could/MAY/MIGHT HAVE done

NEEDN'T HAVE DONE

SHOULD/ OUGHT TO HAVE done

CAN'T HAVE -MUST HAVE done

would have done

We use it to talk about an action someone DID although they didn't have to

We use it to talk about actions that we would have done if we hadn't faced a problem

We're 100% sure something didn't happen or happened in the past

We use it to express criticism, annoyance or regret

We use it to talk about actions that were possible to happen in the past

THANKS!

Maria Theologidou, YES! English Language Centre 2020 -2021