I could retry you could retry he could retry we could retry you could retry they could retry
V-ing form
I could be retrying you could be retrying he could be retrying we could be retrying you could be retrying they could be retrying
Perfect
I could have retried you could have retried he could have retried we could have retried you could have retried they could have retried
V-ing perfect
I could have been retrying you could have been retrying he could have been retrying we could have been retrying you could have been retrying they could have been retrying
Negation
Simple form
I could not retry you could not retry he could not retry we could not retry you could not retry they could not retry
V-ing form
I could not be retrying you could not be retrying he could not be retrying we could not be retrying you could not be retrying they could not be retrying
Perfect
I could not have retried you could not have retried he could not have retried we could not have retried you could not have retried they could not have retried
V-ing perfect
I could not have been retrying you could not have been retrying he could not have been retrying we could not have been retrying you could not have been retrying they could not have been retrying
Interrogative form
Simple form
could I retry? could you retry? could he retry? could we retry? could you retry? could they retry?
V-ing form
could I be retrying? could you be retrying? could he be retrying? could we be retrying? could you be retrying? could they be retrying?
Perfect
could I have retried? could you have retried? could he have retried? could we have retried? could you have retried? could they have retried?
V-ing perfect
could I have been retrying? could you have been retrying? could he have been retrying? could we have been retrying? could you have been retrying? could they have been retrying?
Interro-negative form
Simple form
could I not retry? could you not retry? could he not retry? could we not retry? could you not retry? could they not retry?
V-ing form
could I not be retrying? could you not be retrying? could he not be retrying? could we not be retrying? could you not be retrying? could they not be retrying?
Perfect
could I not have retried? could you not have retried? could he not have retried? could we not have retried? could you not have retried? could they not have retried?
V-ing perfect
could I not have been retrying? could you not have been retrying? could he not have been retrying? could we not have been retrying? could you not have been retrying? could they not have been retrying?