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 can't retest you can't retest he can't retest we can't retest you can't retest they can't retest
V-ing form
I can't be retesting you can't be retesting he can't be retesting we can't be retesting you can't be retesting they can't be retesting
Perfect
I can't have retested you can't have retested he can't have retested we can't have retested you can't have retested they can't have retested
V-ing perfect
I can't have been retesting you can't have been retesting he can't have been retesting we can't have been retesting you can't have been retesting they can't 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't I retest? can't you retest? can't he retest? can't we retest? can't you retest? can't they retest?
V-ing form
can't I be retesting? can't you be retesting? can't he be retesting? can't we be retesting? can't you be retesting? can't they be retesting?
Perfect
can't I have retested? can't you have retested? can't he have retested? can't we have retested? can't you have retested? can't they have retested?
V-ing perfect
can't I have been retesting? can't you have been retesting? can't he have been retesting? can't we have been retesting? can't you have been retesting? can't they have been retesting?