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