Modal verbs

Modal verb CAN – Ability

Ex: I can speak some words of greek.
Negative form: I can´t speak Arabic.

Modal verb CAN – Possibility/Permission

Ex: You can park here.

Modal verb CAN – Permission
Ex: Can I go on the school field trip next
week?

Negative form: You can´t miss classes
without a valid reason.

Permission- CAN / MAY

We can use CAN but also MAY.

Ex: I CAN /MAY go on the field trip.

Modal verb MUST – Obligation

Ex: You must do your homework every day.

Modal verb SHOULD - Advice

Ex: You should eat less fast food.

Negative form: You shouldn´t copy while doing the test.

Modal verb MUSTN’T – Prohibition

Ex: You mustn’t drink alcohol and drive. It’s
against the law.

MODAL VERBS

 They are auxiliary verbs we use to

express ability, obligation, prohibition…

 They are invariable
 They are followed by another verb in the infinitive form

PAST

Modal verb CAN – PAST

Ex: In the 1991 cyclone people could get to
the emergency shelters.

Negative form: I couldn´t speak English when I
was 6.

Modal verb MUST – PAST

Ex: You had to go to school every day.

Negative: We didn’t have to wear a uniform at our
school.

POSSIBILITY

What is it?

It MUST be a duck.

It MIGHT / COULD be a rabbit.

It CAN’T be a kangaroo.

MUST = CERTAINTY
MIGHT / COULD = POSSIBILITY
CAN´T = IMPOSSIBILITY

Going Up or Down?