Modal Verbs of Deduction
MUST, MIGHT and CAN'T
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".
| Modal | Meaning | Example |
|---|---|---|
| MUST | I'm very sure | She must be a vampire. |
| MIGHT COULD | I think it's possible | She might be hungry. She could be hungry. |
| CAN'T | It's impossible | She 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