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