Speak About:

Present

Past

Past to Present

Future

Abilities - Responsibilities

Asking Questions

Choosing the Right Phrase

Combining Verbs

Explaining Ideas

Describing Your World

Complex Ideas

Relating Ideas, People, Objects

Speaking about Objects

Wondering about Situations

What Was Probably True

Modal Verbs of Probability - Past

Modal verbs of probability express an opinion based on what a speaker knows about a situation at the moment of speaking. The following forms are used to speak about past situations.

Example:

The bank guarantee could have been available last week.

There might have been insufficient funds to cover the withdrawal.

I could have been rich if I had done a better job with managed liabilities.

'Must' plus the perfect form (must have done) expresses the idea that you are almost 100% sure of your opinion about a given situation which took place in the past.

Subject + must + have + past participle + objects

Example:

They must have been involved in securing the endorsement.

He must have been aware the endorsement would reflect poorly on the candidate.

'Might' or 'could' plus the perfect form of the verb (could / might have done) expresses an opinion that you think was probably true at a past moment in time.

Subject + might / could + have + past participle + objects

Example:

I could have been rich if I had done a better job with managed liabilities.

The bank guarantee could have been available last week.

'Can't' plus the perfect form of the verb (can't have done) expresses the idea that you are almost 100% sure that something was not true at a past moment in time. Note that the form is 'can't have done' NOT 'couldn't have done'.

Subject + can't + have + past participle + objects

Example:

A commercial loan can't have been given to that builder.

That can't have been a bear market because I made a lot of money