> For the complete documentation index, see [llms.txt](https://viktor-8.gitbook.io/untitled/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://viktor-8.gitbook.io/untitled/english/past-modal-verbs-of-deduction/exercises.md).
# Exercises
Past modal verbs of deduction
### Exercise 1
1. Nobody knows exactly why he died. But we think it **might have** been an accident.
{% hint style="info" %}
We can use **might/may have + past participle** to talk about something that perhaps happened or was true.\
We can use **can't** but not **can** as a modal verb of deduction.\
*It might have been an accident* = Maybe it was an accident.
{% endhint %}
2. I **should have** revised more for the exam. I was lazy, and now I'll fail!
{% hint style="info" %}
We can use **should have + past participle** to talk about a situation that we expected to happen in the past, but it didn't.\
We often use this form to express criticism.
{% endhint %}
3. Sarah looked very happy. She **must have** passed her driving test.
{% hint style="info" %}
We can use **must have + past participle** to say that we are quite sure that something **was true or happened in the past**.\
*She must have passed her diriving test* = I'm sure she passed.
{% endhint %}
4. I didn't know you were going to Phil's party yesterday. You **should have** told me!
{% hint style="info" %}
We can use **should have + past participle** to talk about a situation that we expected to happen in the past, but it didn’t.\
We often use this form to express criticism.
{% endhint %}
5. I can't believe Jim hasn't arrived yet. He **must have** taken the wrong train.
{% hint style="info" %}
We can use **must have + past participle** to say that we are quite sure that something **was true or happened in the past**.\
*He must have taken the wrong train* = I’m sure she took the wrong train.
{% endhint %}
6. I can't believe Jim hasn't arrived yet. He **can't have** taken the correct train.
{% hint style="info" %}
We can use **can’t/couldn’t have + past participle** to say that we are **quite sure that something did NOT happen or was NOT true in the past**.\
*He can't have taken the correct train*. = I'm quite sure he didn't take the correct train.
{% endhint %}
7. You **couldn't have** been ill yesterday. Jessie saw you at the bowling alley.
{% hint style="info" %}
We can use **can’t/couldn’t have + past participle** to say that we are **quite sure that something did NOT happen or was NOT true in the past**.\
*You couldn't have been ill.=* I'm quite sure you weren't ill.\
We can use **must** but not **mustn't** as a modal verb of deduction.
{% endhint %}
8. I don't know where they went but they **could have** gone to Paris or Marseille.
{% hint style="info" %}
We can use **could/might/may have + past participle** to talk about something that perhaps happened or was true.\
*They could have gone to Paris or Marseille.*= Perhaps they went Paris or Marseille.\
We can use **can't** but not **can** as a modal verb of deduction.
{% endhint %}
9. You **ought to have** paid more attention. Now we are lost.
{% hint style="info" %}
We can use **should/ought to have + past participle** to talk about a situation that we expected to happen in the past, but it didn’t.\
We often use this form to express criticism.
{% endhint %}
10. The window was broken, so the thieves **must have** got in through that window.
{% hint style="info" %}
We can use **must have + past participle** to say that we are quite sure that something **was true or happened in the past**.\
*The thieves must have got in through that window.* = I'm quite sure the thieves got in through that window.
{% endhint %}