could roof
Regular verb: roof - roofed- roofed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could roof
you could roof
she could roof
we could roof
you could roof
they could roof 	I could be roofing
you could be roofing
she could be roofing
we could be roofing
you could be roofing
they could be roofing	I could have roofed
you could have roofed
she could have roofed
we could have roofed
you could have roofed
they could have roofed	I could have been roofing
you could have been roofing
she could have been roofing
we could have been roofing
you could have been roofing
they could have been roofing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not roof
you could not roof
she could not roof
we could not roof
you could not roof
they could not roof 	I could not be roofing
you could not be roofing
she could not be roofing
we could not be roofing
you could not be roofing
they could not be roofing	I could not have roofed
you could not have roofed
she could not have roofed
we could not have roofed
you could not have roofed
they could not have roofed	I could not have been roofing
you could not have been roofing
she could not have been roofing
we could not have been roofing
you could not have been roofing
they could not have been roofing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I roof?
could you roof?
could she roof?
could we roof?
could you roof?
could they roof? 	could I be roofing?
could you be roofing?
could she be roofing?
could we be roofing?
could you be roofing?
could they be roofing? 	could I have roofed?
could you have roofed?
could she have roofed?
could we have roofed?
could you have roofed?
could they have roofed? 	could I have been roofing?
could you have been roofing?
could she have been roofing?
could we have been roofing?
could you have been roofing?
could they have been roofing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not roof?
could you not roof?
could she not roof?
could we not roof?
could you not roof?
could they not roof? 	could I not be roofing?
could you not be roofing?
could she not be roofing?
could we not be roofing?
could you not be roofing?
could they not be roofing? 	could I not have roofed?
could you not have roofed?
could she not have roofed?
could we not have roofed?
could you not have roofed?
could they not have roofed? 	could I not have been roofing?
could you not have been roofing?
could she not have been roofing?
could we not have been roofing?
could you not have been roofing?
could they not have been roofing?