I could den you could den she could den we could den you could den they could den
V-ing form
I could be dening you could be dening she could be dening we could be dening you could be dening they could be dening
Perfect
I could have dened you could have dened she could have dened we could have dened you could have dened they could have dened
V-ing perfect
I could have been dening you could have been dening she could have been dening we could have been dening you could have been dening they could have been dening
Negation
Simple form
I couldn't den you couldn't den she couldn't den we couldn't den you couldn't den they couldn't den
V-ing form
I couldn't be dening you couldn't be dening she couldn't be dening we couldn't be dening you couldn't be dening they couldn't be dening
Perfect
I couldn't have dened you couldn't have dened she couldn't have dened we couldn't have dened you couldn't have dened they couldn't have dened
V-ing perfect
I couldn't have been dening you couldn't have been dening she couldn't have been dening we couldn't have been dening you couldn't have been dening they couldn't have been dening
Interrogative form
Simple form
could I den? could you den? could she den? could we den? could you den? could they den?
V-ing form
could I be dening? could you be dening? could she be dening? could we be dening? could you be dening? could they be dening?
Perfect
could I have dened? could you have dened? could she have dened? could we have dened? could you have dened? could they have dened?
V-ing perfect
could I have been dening? could you have been dening? could she have been dening? could we have been dening? could you have been dening? could they have been dening?
Interro-negative form
Simple form
couldn't I den? couldn't you den? couldn't she den? couldn't we den? couldn't you den? couldn't they den?
V-ing form
couldn't I be dening? couldn't you be dening? couldn't she be dening? couldn't we be dening? couldn't you be dening? couldn't they be dening?
Perfect
couldn't I have dened? couldn't you have dened? couldn't she have dened? couldn't we have dened? couldn't you have dened? couldn't they have dened?
V-ing perfect
couldn't I have been dening? couldn't you have been dening? couldn't she have been dening? couldn't we have been dening? couldn't you have been dening? couldn't they have been dening?