Modal Verbs and the Past Tense

This post is in response to a question from a student about whether it is ever correct to use "have have" when using modal verbs in the past tense.

The modal verbs we use when referring to events that have taken place in the past are: could, would, may, might, should and must.

When constructing a sentence using modal verbs to talk about the past we use the pronoun and then have been or have had. 

*We never use "have have" in modal sentences referring to the past. In fact, the use of "have have" is never grammatically correct in the English language.

There are situations when we use the phrase "have to have" in a sentence. It is used to talk about needing something because it is absolutely essential or necessary.

Here are two examples:

I have to have an operation on my elbow. (It is essential for my health to have the operation.)

I just have to have that blouse. (I view the blouse to be an essential purchase based on my desires.)

These sentences can be changed into the past tense. See the examples below. Notice how the first have becomes had.

I had to have an operation on my elbow. (It was essential for my health to have the operation.)

I just had to have that blouse. (I viewed the blouse to be an essential purchase based on my desires.)

See the following examples below of how to use have been and have had with modal verbs to talk about the past:

I could have been very wealthy if I had worked harder.

I could have had a lot of money if I had worked harder.

You would have had better health if you had not smoked when you were younger.

You would have been healthier if you had not smoked when you were younger.

He may have been a teacher when he was younger.

He may have had a job as a teacher when he was younger.

She might have been a doctor if she had had the chance.

She might have had a career as a doctor if she had had the chance.

It should have been serviced last year.

It should have had a service last year.

We must have been to France at least five times for a holiday.

We must have had five holidays in France.

You should have been a lawyer rather than a musician.

You should have had a career as a lawyer rather than a career as a musician.

They must have been living in London in the 1970's.

They must have had a house in London in the 1970's.

All of the examples demonstrate that in English we use have been or have had with a modal verb to refer to the past and that we NEVER use "have have".