I could deforce you could deforce she could deforce we could deforce you could deforce they could deforce
V-ing form
I could be deforcing you could be deforcing she could be deforcing we could be deforcing you could be deforcing they could be deforcing
Perfect
I could have deforced you could have deforced she 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 she 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 she 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 she 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 she 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 she 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 she deforce? could we deforce? could you deforce? could they deforce?
V-ing form
could I be deforcing? could you be deforcing? could she be deforcing? could we be deforcing? could you be deforcing? could they be deforcing?
Perfect
could I have deforced? could you have deforced? could she 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 she 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 she 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 she 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 she 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 she have been deforcing? couldn't we have been deforcing? couldn't you have been deforcing? couldn't they have been deforcing?