I can mar you can mar he can mar we can mar you can mar they can mar
V-ing form
I can be marring you can be marring he can be marring we can be marring you can be marring they can be marring
Perfect
I can have marred you can have marred he can have marred we can have marred you can have marred they can have marred
V-ing perfect
I can have been marring you can have been marring he can have been marring we can have been marring you can have been marring they can have been marring
Negation
Simple form
I cannot mar you cannot mar he cannot mar we cannot mar you cannot mar they cannot mar
V-ing form
I cannot be marring you cannot be marring he cannot be marring we cannot be marring you cannot be marring they cannot be marring
Perfect
I cannot have marred you cannot have marred he cannot have marred we cannot have marred you cannot have marred they cannot have marred
V-ing perfect
I cannot have been marring you cannot have been marring he cannot have been marring we cannot have been marring you cannot have been marring they cannot have been marring
Interrogative form
Simple form
can I mar? can you mar? can he mar? can we mar? can you mar? can they mar?
V-ing form
can I be marring? can you be marring? can he be marring? can we be marring? can you be marring? can they be marring?
Perfect
can I have marred? can you have marred? can he have marred? can we have marred? can you have marred? can they have marred?
V-ing perfect
can I have been marring? can you have been marring? can he have been marring? can we have been marring? can you have been marring? can they have been marring?
Interro-negative form
Simple form
can I not mar? can you not mar? can he not mar? can we not mar? can you not mar? can they not mar?
V-ing form
can I not be marring? can you not be marring? can he not be marring? can we not be marring? can you not be marring? can they not be marring?
Perfect
can I not have marred? can you not have marred? can he not have marred? can we not have marred? can you not have marred? can they not have marred?
V-ing perfect
can I not have been marring? can you not have been marring? can he not have been marring? can we not have been marring? can you not have been marring? can they not have been marring?