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 couldn't roof
you couldn't roof
she couldn't roof
we couldn't roof
you couldn't roof
they couldn't roof 	I couldn't be roofing
you couldn't be roofing
she couldn't be roofing
we couldn't be roofing
you couldn't be roofing
they couldn't be roofing	I couldn't have roofed
you couldn't have roofed
she couldn't have roofed
we couldn't have roofed
you couldn't have roofed
they couldn't have roofed	I couldn't have been roofing
you couldn't have been roofing
she couldn't have been roofing
we couldn't have been roofing
you couldn't have been roofing
they couldn't 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 	
couldn't I roof?
couldn't you roof?
couldn't she roof?
couldn't we roof?
couldn't you roof?
couldn't they roof? 	couldn't I be roofing?
couldn't you be roofing?
couldn't she be roofing?
couldn't we be roofing?
couldn't you be roofing?
couldn't they be roofing? 	couldn't I have roofed?
couldn't you have roofed?
couldn't she have roofed?
couldn't we have roofed?
couldn't you have roofed?
couldn't they have roofed? 	couldn't I have been roofing?
couldn't you have been roofing?
couldn't she have been roofing?
couldn't we have been roofing?
couldn't you have been roofing?
couldn't they have been roofing?