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