I could man you could man he could man we could man you could man they could man
V-ing form
I could be manning you could be manning he could be manning we could be manning you could be manning they could be manning
Perfect
I could have manned you could have manned he could have manned we could have manned you could have manned they could have manned
V-ing perfect
I could have been manning you could have been manning he could have been manning we could have been manning you could have been manning they could have been manning
Negation
Simple form
I could not man you could not man he could not man we could not man you could not man they could not man
V-ing form
I could not be manning you could not be manning he could not be manning we could not be manning you could not be manning they could not be manning
Perfect
I could not have manned you could not have manned he could not have manned we could not have manned you could not have manned they could not have manned
V-ing perfect
I could not have been manning you could not have been manning he could not have been manning we could not have been manning you could not have been manning they could not have been manning
Interrogative form
Simple form
could I man? could you man? could he man? could we man? could you man? could they man?
V-ing form
could I be manning? could you be manning? could he be manning? could we be manning? could you be manning? could they be manning?
Perfect
could I have manned? could you have manned? could he have manned? could we have manned? could you have manned? could they have manned?
V-ing perfect
could I have been manning? could you have been manning? could he have been manning? could we have been manning? could you have been manning? could they have been manning?
Interro-negative form
Simple form
could I not man? could you not man? could he not man? could we not man? could you not man? could they not man?
V-ing form
could I not be manning? could you not be manning? could he not be manning? could we not be manning? could you not be manning? could they not be manning?
Perfect
could I not have manned? could you not have manned? could he not have manned? could we not have manned? could you not have manned? could they not have manned?
V-ing perfect
could I not have been manning? could you not have been manning? could he not have been manning? could we not have been manning? could you not have been manning? could they not have been manning?