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