I can retest you can retest he can retest we can retest you can retest they can retest
V-ing form
I can be retesting you can be retesting he can be retesting we can be retesting you can be retesting they can be retesting
Perfect
I can have retested you can have retested he can have retested we can have retested you can have retested they can have retested
V-ing perfect
I can have been retesting you can have been retesting he can have been retesting we can have been retesting you can have been retesting they can have been retesting
Negation
Simple form
I cannot retest you cannot retest he cannot retest we cannot retest you cannot retest they cannot retest
V-ing form
I cannot be retesting you cannot be retesting he cannot be retesting we cannot be retesting you cannot be retesting they cannot be retesting
Perfect
I cannot have retested you cannot have retested he cannot have retested we cannot have retested you cannot have retested they cannot have retested
V-ing perfect
I cannot have been retesting you cannot have been retesting he cannot have been retesting we cannot have been retesting you cannot have been retesting they cannot have been retesting
Interrogative form
Simple form
can I retest? can you retest? can he retest? can we retest? can you retest? can they retest?
V-ing form
can I be retesting? can you be retesting? can he be retesting? can we be retesting? can you be retesting? can they be retesting?
Perfect
can I have retested? can you have retested? can he have retested? can we have retested? can you have retested? can they have retested?
V-ing perfect
can I have been retesting? can you have been retesting? can he have been retesting? can we have been retesting? can you have been retesting? can they have been retesting?
Interro-negative form
Simple form
can I not retest? can you not retest? can he not retest? can we not retest? can you not retest? can they not retest?
V-ing form
can I not be retesting? can you not be retesting? can he not be retesting? can we not be retesting? can you not be retesting? can they not be retesting?
Perfect
can I not have retested? can you not have retested? can he not have retested? can we not have retested? can you not have retested? can they not have retested?
V-ing perfect
can I not have been retesting? can you not have been retesting? can he not have been retesting? can we not have been retesting? can you not have been retesting? can they not have been retesting?