Learning English
Grammar Rules: ▼ Tenses ▼ Futures ▼ Conditionals ▼ Relative Clauses ▼ Passives ▼ Reported Speech ▼ Questions ▼ Articles ▼ Adjectives ▼ Modal Verbs ▼ Gerunds/Infinitives
Grammar Exercises
Grammar Terms
Vocabulary
Prepositions
FCE practice

Modal Verbs of Deduction

 

MUST, MIGHT and CAN'T


vampire modal verbs of obligation

Look at her teeth! She must be a vampire.

Be careful. She might be hungry.

She can't be a vampire - they don't exist!


Note: We never use "can" or "mustn't" with this meaning - only "must" and "can't".


ModalMeaningExample
MUSTI'm very sureShe must be a vampire.
MIGHT
COULD
I think it's possibleShe might be hungry.
She could be hungry.
CAN'TIt's impossibleShe can't be a vampire.

Modal verbs are always followed by the infinitive (without 'to'). But you need to decide if you are talking about a state, an action in progress, or a finished action/state.


Present States
He might be at home now.
modal + infinitive
Actions in progress now
He might be working now.
modal + be + verb-ing
Past Actions/States
He might have gone out.
modal + have + past participle

If you can't remember the difference between actions and states, you can read more about it on my state verbs pages.


Practice these modal verbs

Sponsors