Modal verbs for deduction grammar in English

Language: English
Level: B2
Unit: Modal Verbs
Practice types: 0

What this grammar point covers

Modal verbs for deduction are words like 'must', 'might', 'may', and 'can't' that we use to say how sure or unsure we are about something.

When to use it

We use these forms when we want to guess or make conclusions about a situation. For example, when we see something and think about what is probably true or not true.

Key forms

must + base verb
might/may/could + base verb
can't + base verb
must/might/may/could/can't + have + past participle

Examples

She must be at work.

He might be sleeping.

They can't be serious.

You must have left your keys at home.

She could have forgotten the meeting.

Tips

Don't use 'to' after modal verbs: say 'must go', not 'must to go'.
Use 'have + past participle' to talk about the past: 'must have seen'.
Remember: 'must' is for things you are sure about; 'might', 'may', and 'could' are for things you are not sure about.