have had to,had had to?

[atlaisha]

Today there was a discussion in my English class about the following structure,our teacher said that even if it is grammatically correct it is rarely ever used,finally she asked me toask your opinion on this.Here are the sentences:

-If i hadn't had to think of school,my vacation would have been a greater one.

or:

-If I had forgotten the key,I would have had to call a ....

Considering the words have had to and had had to,

Please tell me if they are grammatically right,and if they are,are they common to be used by native speakers in their everyday conversations?Also please tell me if being correct or not has to do with mixed conditionals.

Endless thanks for taking time on my questions and helping me with my English.

 

[riverkid]

Today there was a discussion in my English class about the following structure,our teacher said that even if it is grammatically correct it is rarely ever used,finally she asked me to ask your opinion on this. Here are the sentences:

-If I hadn't had to think of school, my vacation would have been a greater one.

or:

-If I had forgotten the key, I would have had to call a ....

I expect that you mean this, have had to, as it is used in the part I've put in red, above.

Considering the words have had to and had had to,

Please tell me if they are grammatically right,

Yes, they are.

and if they are,are they common to be used by native speakers in their everyday conversations?

Yes, they are.

Also please tell me if being correct or not has to do with mixed conditionals.

There are no mixed conditionals in either one that I can see.

Endless thanks for taking time on my questions and helping me with my English.

You're very welcome, Atlaisha.