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