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