could proof
Regular verb: proof - proofed- proofed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could proof
you could proof
he could proof
we could proof
you could proof
they could proof 	I could be proofing
you could be proofing
he could be proofing
we could be proofing
you could be proofing
they could be proofing	I could have proofed
you could have proofed
he could have proofed
we could have proofed
you could have proofed
they could have proofed	I could have been proofing
you could have been proofing
he could have been proofing
we could have been proofing
you could have been proofing
they could have been proofing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't proof
you couldn't proof
he couldn't proof
we couldn't proof
you couldn't proof
they couldn't proof 	I couldn't be proofing
you couldn't be proofing
he couldn't be proofing
we couldn't be proofing
you couldn't be proofing
they couldn't be proofing	I couldn't have proofed
you couldn't have proofed
he couldn't have proofed
we couldn't have proofed
you couldn't have proofed
they couldn't have proofed	I couldn't have been proofing
you couldn't have been proofing
he couldn't have been proofing
we couldn't have been proofing
you couldn't have been proofing
they couldn't have been proofing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I proof?
could you proof?
could he proof?
could we proof?
could you proof?
could they proof? 	could I be proofing?
could you be proofing?
could he be proofing?
could we be proofing?
could you be proofing?
could they be proofing? 	could I have proofed?
could you have proofed?
could he have proofed?
could we have proofed?
could you have proofed?
could they have proofed? 	could I have been proofing?
could you have been proofing?
could he have been proofing?
could we have been proofing?
could you have been proofing?
could they have been proofing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I proof?
couldn't you proof?
couldn't he proof?
couldn't we proof?
couldn't you proof?
couldn't they proof? 	couldn't I be proofing?
couldn't you be proofing?
couldn't he be proofing?
couldn't we be proofing?
couldn't you be proofing?
couldn't they be proofing? 	couldn't I have proofed?
couldn't you have proofed?
couldn't he have proofed?
couldn't we have proofed?
couldn't you have proofed?
couldn't they have proofed? 	couldn't I have been proofing?
couldn't you have been proofing?
couldn't he have been proofing?
couldn't we have been proofing?
couldn't you have been proofing?
couldn't they have been proofing?