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 could not proof
you could not proof
he could not proof
we could not proof
you could not proof
they could not proof 	I could not be proofing
you could not be proofing
he could not be proofing
we could not be proofing
you could not be proofing
they could not be proofing	I could not have proofed
you could not have proofed
he could not have proofed
we could not have proofed
you could not have proofed
they could not have proofed	I could not have been proofing
you could not have been proofing
he could not have been proofing
we could not have been proofing
you could not have been proofing
they could not 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 	
could I not proof?
could you not proof?
could he not proof?
could we not proof?
could you not proof?
could they not proof? 	could I not be proofing?
could you not be proofing?
could he not be proofing?
could we not be proofing?
could you not be proofing?
could they not be proofing? 	could I not have proofed?
could you not have proofed?
could he not have proofed?
could we not have proofed?
could you not have proofed?
could they not have proofed? 	could I not have been proofing?
could you not have been proofing?
could he not have been proofing?
could we not have been proofing?
could you not have been proofing?
could they not have been proofing?