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