NHP Int Unit 9 Past Probability

NHP Int Unit 9 Past Probability

Past probability

• We use the perfect infinitive

• 1 We form the perfect infinitive with have + past participle.

   She must have missed her bus.

   They might have forgotten.

2 These forms express degrees of probability in the past, from sure to less sure.

• (Sure) They must have been so happy.

•  He can’t have heard the news.

•  She may have mentioned it.

•  They might have gone to the park.

•  (Less sure) The train could have been delayed. (passive)

3 We form the continuous infinitive with have + been + -ing.

•  They must have been having a good time.

  
  

•  She might have been telling the truth

Respond to the statement in Ex 1 Page 73 student book.

• I can't find my homework. (must/forget)

• You must have forgotten it.

Open Ended

2. must /ill

Open Ended

3. might/oversleep

Open Ended

4. must/drop

Open Ended

5. can't/finish already

Open Ended

6. must/cheat

Workbook Ex 4 Page 58

• Look at the pictures.

• Write two statements about what must/might/may/could have happened.

• He must have locked himself out.

• He might have lost his keys.

Open Ended

2.

Open Ended

3.

Open Ended

4.

Open Ended

5.

Open Ended

6.

What are the five forms of Past probability? (modal + have + v3)

• must have (sure probable)

• can't have (sure improbable)

• might have (50/50)

• may have (50/50)

• could have (less sure - don't really know)

Change this sentence using 'must'.

• I'm sure she's had a holiday. (must)

• She must have had a holiday.

Workbook Page 58 Ex 5

• Rewrite the sentences using the modal verb in brackets.

Open Ended

2. can't

Open Ended

3. could

Open Ended

4. might

Open Ended

5. can't

Open Ended

6. must

Open Ended

7. could

Open Ended

8. may

Workbook Ex 6 P59

• Write sentences for each of the eight situations, using the information in the box.

Example

• I don't know why Tom is so late.

• He must have missed the bus.

• Now answer questions 2 to 8

Open Ended

2.

Open Ended

3.

Open Ended

4.

Open Ended

5.

Open Ended

6.

Open Ended

7.

Open Ended

8.

Possible answers:

• She might have left it in the taxi.

• She can't have got good marks in her exam.

• They must have enjoyed the film.

• He can't have cleaned it recently.

• They must have arrived home by now.

• They must have gone home without me.

• He could have gone to France.

Workbook P59 Ex 7

• Complete the conversations, putting the verbs in brackets into the correct form