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