I can proof you can proof he can proof we can proof you can proof they can proof
V-ing form
I can be proofing you can be proofing he can be proofing we can be proofing you can be proofing they can be proofing
Perfect
I can have proofed you can have proofed he can have proofed we can have proofed you can have proofed they can have proofed
V-ing perfect
I can have been proofing you can have been proofing he can have been proofing we can have been proofing you can have been proofing they can have been proofing
Negation
Simple form
I cannot proof you cannot proof he cannot proof we cannot proof you cannot proof they cannot proof
V-ing form
I cannot be proofing you cannot be proofing he cannot be proofing we cannot be proofing you cannot be proofing they cannot be proofing
Perfect
I cannot have proofed you cannot have proofed he cannot have proofed we cannot have proofed you cannot have proofed they cannot have proofed
V-ing perfect
I cannot have been proofing you cannot have been proofing he cannot have been proofing we cannot have been proofing you cannot have been proofing they cannot have been proofing
Interrogative form
Simple form
can I proof? can you proof? can he proof? can we proof? can you proof? can they proof?
V-ing form
can I be proofing? can you be proofing? can he be proofing? can we be proofing? can you be proofing? can they be proofing?
Perfect
can I have proofed? can you have proofed? can he have proofed? can we have proofed? can you have proofed? can they have proofed?
V-ing perfect
can I have been proofing? can you have been proofing? can he have been proofing? can we have been proofing? can you have been proofing? can they have been proofing?
Interro-negative form
Simple form
can I not proof? can you not proof? can he not proof? can we not proof? can you not proof? can they not proof?
V-ing form
can I not be proofing? can you not be proofing? can he not be proofing? can we not be proofing? can you not be proofing? can they not be proofing?
Perfect
can I not have proofed? can you not have proofed? can he not have proofed? can we not have proofed? can you not have proofed? can they not have proofed?
V-ing perfect
can I not have been proofing? can you not have been proofing? can he not have been proofing? can we not have been proofing? can you not have been proofing? can they not have been proofing?