Used to give possible reasons why something happened or didn ’ t happen in the past.

Part 1 May have... Might have... Could have... *used to give possible explanations for past events

Why didn ’ t John come out to lunch with us yesterday? I ’ m not sure. He might have had too much work to do. He may have been busy at work. He could have gone to a meeting.

Why was Tomas late to class on Monday? I ’ m not sure. He might have woken up late. He may have missed the bus. He could have forgotten to change his clock.

What do you think your husband got you for your anniversary? I don ’ t know. He might have gotten me some jewelry. He may have bought me a new kitchen appliance. He could have picked out some perfume for me.

I wonder why Susan seemed so sad yesterday. I ’ m not sure. She might have received some bad news. She might have felt ill. She may have broken up with her boyfriend.

I wonder why the teacher wasn ’ t in class on Friday. He may have been ill. He might have gone rock climbing. He might have decided to take a relaxing day off.

Part 2 Must have... *stronger than -may have -might have -could have

Meaning / Use: Must have = similar to the use of may/might/could have… Must have shows more certainty than may/might/could have… Use must have + past participle to show a strong probability

Comparison: may/might/could have… versus must have… John wasn ’ t in class today. I wonder why... He could have been ill. OR He may not have felt well. He must have been ill. OR He must not have felt well.

Jan looks really tired today. It ’ s strange to see her this way because she is usually very energetic. She must not have gotten very much sleep last night.

Did you see how well Sam played during the soccer game? I was really surprised that he scored 4 goals because he usually doesn ’ t play that well. He must have practiced a lot before the game. OR He must have been practicing a lot recently. (progressive form)

Structure: How to make this grammar May Might Could Must

For the NEGATIVE: May Might Could Must

Negative Examples: Richard ’ s wife bought a new table 2 weeks ago, but Richard still hasn ’ t assembled it. I wonder why? He must NOT have understood the instructions.

Pronunciation Tips: When you hear native speakers use this grammar, it often sounds like they are saying: “ might-uv ” or “ might-a ” “ may-uv ” or “ may-a ” “ could-uv ” or “ could-a ” “ must-uv ” or “ must-a ”

She might have left already. They could have misunderstood the instructions. Susan might have quit her job. She must have gone home early today. Cynthia might have tried to call me when I out walking my dog.

Now it ’ s YOUR turn! What do you think? What are some possible reasons why these things happened? Write them on a piece of paper and show your writing to your teacher.

1.I wonder why Janet didn ’ t come to school today? 2.I wonder why Lisa and her husband decided to move to Temecula. 3. I wonder what my mother got me for my birthday.

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