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