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