modal verbs of deduction

We use these when we are talking about something we guess is true based on the information we have.

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​Modal verbs of deduction

Use "must" when you are very sure something is true.

• ​Sally and Larry went to primary school together so they must know each other.

​Must

Multiple Choice

Choose the correct modal verb of deduction:

Peter is wearing a think, winter coat, it …. be cold outside!

• Should

• May

• Must

• Can’t

Use "can´t" when you are very sure something is NOT true.

• ​The person in the photo can´t be Sally because Sally has blue eyes.

Can´t

Use "may" or "might" when you are not very sure if something is true.

• ​Next week is the Easter holidays and we might be going to visit our cousins in Madrid.

May/Might

To make a specualtion about something in progress at that moment.

• ​I cna hear a lot of noise in the classroom next door, they might be playing a blooket.

modal verb + be +-ing

To make a specualtion about something that has already happened:

Modal verb + have + past participle

• Mark didn´t go to his friend´s birthday party yesterday, he must have been sick.

Modal verbs of deduction to talk about the past

Multiple Choice

Choose the correct verb:

He …. washed the dishes last night because the sink is still full of dirty dishes now!

• can’t have

• didn’t have

• won’t have

• can’t

Multiple Choice

Choose the correct option:

They sent the books I ordered online yesterday so they …. by now.

• Might have arrive

• Might arrive

• Might have arrived

• Might arrived