May not have; can't have; had to ; must have

 Here is a chart that shows the differences between "may not have," "can't have," "had to," and "must have":

Phrase	Meaning	Example	Usage
May not have	Possibility of not happening	She may not have received my email.	Used to express doubt or uncertainty about a past event.
Can't have	Impossibility of happening	He can't have finished the project already.	Used to express certainty that something did not happen.
Had to	Obligation or requirement	I had to finish my work before leaving.	Used to describe a past obligation or requirement.
Must have	Strong likelihood	They must have left early.	Used to express a strong belief or likelihood about a past event.

Here are some examples and exercises to illustrate the use of these phrases:

1. May not have:

• "He may not have seen the message yet." - Here, "may not have" is used to express doubt or uncertainty about whether or not he has seen the message.

Exercise: Use "may not have" to express doubt about whether or not a friend received your invitation to a party.

2. Can't have:

• "I can't have left my keys at work, I remember putting them in my pocket." - Here, "can't have" is used to express certainty that the keys were not left at work.

Exercise: Use "can't have" to express certainty that you did not forget your phone at home.

3. Had to:

• "I had to work late last night." - Here, "had to" is used to describe a past obligation to work late.

Exercise: Use "had to" to describe a past obligation to attend a family event.

4. Must have:

• "She must have forgotten about the meeting." - Here, "must have" is used to express a strong belief or likelihood that she forgot about the meeting.

Exercise: Use "must have" to express a strong belief that a friend did not hear you calling their name.

It's important to note that these phrases are used to describe past events or situations, and their use can depend on the context and speaker's intention.