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