might have finished by next week.

[Vladv1]

Do you agree that "By next week, he may/might/should have finished" is extremely rare and often sounds awkward?

 

[5jj]

I do not.

What do you think is awkward?

 

[Vladv1]

I do not.

What do you think is awkward?

So if I am making an assumption I can say. He "should have finished by tomorrow"?

 

[5jj]

You can.

Did you think you couldn't?

 

[jutfrank]

So if I am making an assumption I can say. He "should have finished by tomorrow"?

That's not an assumption. It's an expectation, which is different.

 

[Vladv1]

That's not an assumption. It's an expectation, which is different.

Could you please explain the difference between the two?

 

[Skrej]

What does your trusty dictionary tell you the difference is?

 

[Vladv1]

What does your trusty dictionary tell you the difference is?

Expectation is always aimed at the future.

 

[emsr2d2]

Do you agree that "By next week, he may/might/should have finished" is extremely rare and often sounds awkward?

As a pedant, I'd say it would be very awkward if someone said to me "By next week, he may slash might slash should have finished". Also, if something's "extremely rare" it's not going "often sound" anything!

So if I am making an assumption can I can say no full stop here "He should have finished by tomorrow"?

See above. Make sure you use the correct word order for a question. Don't write a statement and then just stick a question mark at the end.

 

[GJNavigator]

Not a teacher

It doesn’t sound awkward to me. It’s just not very common in everyday conversation, but it’s perfectly natural in the right context.

 

[Tarheel]

CAN I say, "He should have finished by tomorrow"?

Perhaps:

He should be finished by tomorrow.