UNIT 13

GRAMMAR

*

Modals: ability, permission, advice, criticism, obligation and necessity, degrees of

certainty

Form • All modals (will, would, shall, should, can, could, may, might,must) and the semi-

modal ought to have only one form.

• Modals are followed by the bare infinitive (simple or continuous) or the bare perfect

infinitive eg Toby should be very fit by now.

Toby should have recovered by now.

• The semi-modals have to and need to change their form depending on person and tense

eg The doctor said I had/needed to give up red meat.

Modals: ability

Use

Modal

Example

Expressing ability now or generally

can

I can run a kilometre in four minutes.

Expressing decisions made now

about future ability

can

We can meet at the gym tomorrow, if you like.

Expressing ability in the past

could

I could do fifty press-ups with one hand when 1

was younger.

Expressing ability in present, future

or general hypothetical situations

could

If only I could quit smoking!

Expressing ability in past

hypothetical situations

could +

perfect

infinitive

I could have roasted the potatoes, but 1 decided

that boiling them was healthier.



We use be able to for the infini tive and other tenses.

√ I’d love to be able to fit into these jeans again! (infinitive)

√ I’ll be able to leave hospital in a few weeks, apparently, (future)

√ I've been able to swim since 1 was five, (present perfect)

Modals: permission

Use

Modal

Example

Asking for and giving permission

now, for the future or generally

may

could

can

May / Could / Can I see the doctor, please?



May is more polite than could, and could is more polite than can.



We don't usually use a modal to talk about past permission.

√ I was allowed to wear a knee support during the match.

X I could wear a knee support during the match.



However, we do use could to talk about past permission in reported

speech.

√ The coach said I could wear a knee support during the match.