A Grammar of the English Tongue

by Samuel Johnson

Sing. I shall have had, thou shalt have had, he shall have had;

Plur. We shall have had, ye shall have had, they shall have had.

Potential.

The potential form of speaking is expressed by may, can, in the present; and might, could, or should, in the preterit, joined with the infinitive mood of the verb.

Present.

Sing. I may have, thou mayst have, he may have;

Plur. We may have, ye may have, they may have.

Preterit.

Sing. I might have, thou mightst have, he might have;

Plur. We might have, ye might have, they might have.