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 could not flip you could not flip he could not flip we could not flip you could not flip they could not flip
V-ing form
I could not be flipping you could not be flipping he could not be flipping we could not be flipping you could not be flipping they could not be flipping
Perfect
I could not have flipped you could not have flipped he could not have flipped we could not have flipped you could not have flipped they could not have flipped
V-ing perfect
I could not have been flipping you could not have been flipping he could not have been flipping we could not have been flipping you could not have been flipping they could not 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
could I not flip? could you not flip? could he not flip? could we not flip? could you not flip? could they not flip?
V-ing form
could I not be flipping? could you not be flipping? could he not be flipping? could we not be flipping? could you not be flipping? could they not be flipping?
Perfect
could I not have flipped? could you not have flipped? could he not have flipped? could we not have flipped? could you not have flipped? could they not have flipped?
V-ing perfect
could I not have been flipping? could you not have been flipping? could he not have been flipping? could we not have been flipping? could you not have been flipping? could they not have been flipping?