Might have vs "could have"?

Question

What is the difference between _might have_ and _could have_?> He **might have** come. He might have studied.> He **could have** come. He could have studied.How would you describe a possibility? For example:> It's possible that he **came** from a different culture.> It's possible that he **come** from a different cutlure.

Answer 1

As you've noted, they're quite similar and can in certain cases be exchanged without a true change in meaning.

However, generally speaking, "might have" implies an unknown thing that someone/something had the potential to do so, but it was uncertain. For example:

He might have taken out the trash. This sentence expresses doubt over whether he actually took out the trash.

Or

He might have succeeded if he had practiced. This sentence suggests there is a possibility of success, not a guarantee.

On the other hand, "could have" implies that had some condition been met, something/someone would definitely have been able to do something.

For example:

He could have taken out the trash. This sentence implies that he did not take out the trash but should/had the ability to do so. (Although, in the right context, it could also mean that the speaker is unsure whether he actually took out the trash) This would be a case where the two meanings can be quite similar.

As an example that better demonstrates the difference, we can use:

He could have succeeded if he had practiced more.

While this is still a prediction and not set in stone, it suggests that the speaker is more certain of his success. These differences become more apparent when there's some clause that provides context. Overall, the difference is more about the certainty of the statement. "Might" implies more doubt than "could".