I could widen you could widen he could widen we could widen you could widen they could widen
V-ing form
I could be widening you could be widening he could be widening we could be widening you could be widening they could be widening
Perfect
I could have widened you could have widened he could have widened we could have widened you could have widened they could have widened
V-ing perfect
I could have been widening you could have been widening he could have been widening we could have been widening you could have been widening they could have been widening
Negation
Simple form
I couldn't widen you couldn't widen he couldn't widen we couldn't widen you couldn't widen they couldn't widen
V-ing form
I couldn't be widening you couldn't be widening he couldn't be widening we couldn't be widening you couldn't be widening they couldn't be widening
Perfect
I couldn't have widened you couldn't have widened he couldn't have widened we couldn't have widened you couldn't have widened they couldn't have widened
V-ing perfect
I couldn't have been widening you couldn't have been widening he couldn't have been widening we couldn't have been widening you couldn't have been widening they couldn't have been widening
Interrogative form
Simple form
could I widen? could you widen? could he widen? could we widen? could you widen? could they widen?
V-ing form
could I be widening? could you be widening? could he be widening? could we be widening? could you be widening? could they be widening?
Perfect
could I have widened? could you have widened? could he have widened? could we have widened? could you have widened? could they have widened?
V-ing perfect
could I have been widening? could you have been widening? could he have been widening? could we have been widening? could you have been widening? could they have been widening?
Interro-negative form
Simple form
couldn't I widen? couldn't you widen? couldn't he widen? couldn't we widen? couldn't you widen? couldn't they widen?
V-ing form
couldn't I be widening? couldn't you be widening? couldn't he be widening? couldn't we be widening? couldn't you be widening? couldn't they be widening?
Perfect
couldn't I have widened? couldn't you have widened? couldn't he have widened? couldn't we have widened? couldn't you have widened? couldn't they have widened?
V-ing perfect
couldn't I have been widening? couldn't you have been widening? couldn't he have been widening? couldn't we have been widening? couldn't you have been widening? couldn't they have been widening?