I could restraighten you could restraighten she could restraighten we could restraighten you could restraighten they could restraighten
V-ing form
I could be restraightening you could be restraightening she could be restraightening we could be restraightening you could be restraightening they could be restraightening
Perfect
I could have restraightened you could have restraightened she could have restraightened we could have restraightened you could have restraightened they could have restraightened
V-ing perfect
I could have been restraightening you could have been restraightening she could have been restraightening we could have been restraightening you could have been restraightening they could have been restraightening
Negation
Simple form
I could not restraighten you could not restraighten she could not restraighten we could not restraighten you could not restraighten they could not restraighten
V-ing form
I could not be restraightening you could not be restraightening she could not be restraightening we could not be restraightening you could not be restraightening they could not be restraightening
Perfect
I could not have restraightened you could not have restraightened she could not have restraightened we could not have restraightened you could not have restraightened they could not have restraightened
V-ing perfect
I could not have been restraightening you could not have been restraightening she could not have been restraightening we could not have been restraightening you could not have been restraightening they could not have been restraightening
Interrogative form
Simple form
could I restraighten? could you restraighten? could she restraighten? could we restraighten? could you restraighten? could they restraighten?
V-ing form
could I be restraightening? could you be restraightening? could she be restraightening? could we be restraightening? could you be restraightening? could they be restraightening?
Perfect
could I have restraightened? could you have restraightened? could she have restraightened? could we have restraightened? could you have restraightened? could they have restraightened?
V-ing perfect
could I have been restraightening? could you have been restraightening? could she have been restraightening? could we have been restraightening? could you have been restraightening? could they have been restraightening?
Interro-negative form
Simple form
could I not restraighten? could you not restraighten? could she not restraighten? could we not restraighten? could you not restraighten? could they not restraighten?
V-ing form
could I not be restraightening? could you not be restraightening? could she not be restraightening? could we not be restraightening? could you not be restraightening? could they not be restraightening?
Perfect
could I not have restraightened? could you not have restraightened? could she not have restraightened? could we not have restraightened? could you not have restraightened? could they not have restraightened?
V-ing perfect
could I not have been restraightening? could you not have been restraightening? could she not have been restraightening? could we not have been restraightening? could you not have been restraightening? could they not have been restraightening?