I could feed you could feed she could feed we could feed you could feed they could feed
V-ing form
I could be feeding you could be feeding she could be feeding we could be feeding you could be feeding they could be feeding
Perfect
I could have fed you could have fed she 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 she 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 she 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 she 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 she 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 she 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 she feed? could we feed? could you feed? could they feed?
V-ing form
could I be feeding? could you be feeding? could she be feeding? could we be feeding? could you be feeding? could they be feeding?
Perfect
could I have fed? could you have fed? could she 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 she 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 she 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 she 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 she 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 she have been feeding? couldn't we have been feeding? couldn't you have been feeding? couldn't they have been feeding?