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      You could have left it in the café.     Use modal verb + have + past participle   start learning
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      Use modal verb + have + past participle to make deductions or guesses about past actions or states.   
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      She must have been feeling ill.     Use modal verb + have + been + -ing form   start learning
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      Use modal verb + have + been + -ing form to make deductions about continuous actions or states.   
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      It can't have been stolen from your bag.     Use modal verb + have + been + past participle   start learning
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      Use modal verb + have + been + past participle for deductions using the passive.   
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      I must have deleted the email. I can't find it anymore.    start learning
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      you are almost certain that something is true, based on the evidence     have + past participle (the perfect infinitive) is also used with other modals: should have (been) and would have (been)  
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      The plane could have been delayed by the weather. There's a bad storm at sea.    start learning
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      you think it is possible that something is true, based on the evidence     have + past participle (the perfect infinitive) is also used with other modals: should have (been) and would have (been)  
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      It can't have been the waitress. She wasn't in the room when the bag was stolen.    start learning
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      you are almost certain something is not true or is impossible, based on the evidence     have + past participle (the perfect infinitive) is also used with other modals: should have (been) and would have (been)  
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      To speculate or make a deduction about something that happened in the past,    start learning
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      use the modals: must/could/might/can't/couldn't + have + past participle     It can't have been the young couple because I was looking at them all the time.  
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      To emphasise that an activity was in progress,    start learning
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      use modal + have + been + -ing     The woman must have been working with the guy.  
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     start learning
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      use modal + have + been + past participle     So it must have been stolen when I was taking the photo.  
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      Perhaps Jenna while we were out. Let me check on the answerphone.     must/might/may/could/ can't/ couldn't have   start learning
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      Jenna might have phoned while we were out.   
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      Knock louder. You know he's a bit deaf. I'm sure he didn't hear you.    start learning
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      He can't/couldn't have heard you.   
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      I locked the door. I'm certain. Maybe the thieves got in through the windows.    start learning
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      The thieves might/could /may have got in through the window.   
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      I can't find the final version of the report in my computer. I realised it was impossible that I saved the document.    start learning
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      I realised I couldn't have saved the document.   
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      Ooh, that was a bad knock to your head. I'm certain it hurt a lot.    start learning
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      I don't know why Wanda was late for the meeting. Maybe her plane was delayed.    start learning
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      Her plane might/could/may have been delayed.   
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      I'm sure I've made a mistake. The date looks wrong.    start learning
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      I must have made a mistake.   
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      Paola should have won the race. It's impossible that she was trying hard enough.    start learning
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      She can't/couldn't have been trying hard enough.   
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      Look at her necklace. Are those real diamonds?     Yes. It (?) a fortune! (cost)   start learning
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      Yes. It must have cost a fortune!   
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      I tried phoning Mike four times but he didn't answer.     He (?) his phone or maybe he left it at home. (switch off)   start learning
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      He might/could/may have switched off his phone or maybe he left it at home.   
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      Why was Danielle in the office at midnight?     She (?) late. She had a big meeting the next day. (work)   start learning
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      She must have been working late. She had a big meeting the next day.   
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      I'm sure Len told me you were a doctor.     He (?) of my sister, Rachel, or maybe he confused me with someone else. (think)   start learning
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      He might/could/may have been thinking of my sister, Rachel, or maybe he confused me with someone else.   
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      I've lost my boarding card. It's not in my bag!     You (?) properly. I saw you put it there just now. (look)   start learning
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      You can't/couldn't have looked properly. I saw you put it there just now.   
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      Do you think Yves knows he didn't get the promotion?     I suppose he (?) by the boss but I doubt it. (tell)   start learning
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      I suppose he might/could/may have been told by the boss but I doubt it.   
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