English verb conjugation
COULD ROOF

Regular verb: roof - roofed - roofed

Affirmation

Simple form	V-ing form
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
Perfect	V-ing perfect
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
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
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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?