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 couldn't man you couldn't man he couldn't man we couldn't man you couldn't man they couldn't man
V-ing form
I couldn't be manning you couldn't be manning he couldn't be manning we couldn't be manning you couldn't be manning they couldn't be manning
Perfect
I couldn't have manned you couldn't have manned he couldn't have manned we couldn't have manned you couldn't have manned they couldn't have manned
V-ing perfect
I couldn't have been manning you couldn't have been manning he couldn't have been manning we couldn't have been manning you couldn't have been manning they couldn't 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
couldn't I man? couldn't you man? couldn't he man? couldn't we man? couldn't you man? couldn't they man?
V-ing form
couldn't I be manning? couldn't you be manning? couldn't he be manning? couldn't we be manning? couldn't you be manning? couldn't they be manning?
Perfect
couldn't I have manned? couldn't you have manned? couldn't he have manned? couldn't we have manned? couldn't you have manned? couldn't they have manned?
V-ing perfect
couldn't I have been manning? couldn't you have been manning? couldn't he have been manning? couldn't we have been manning? couldn't you have been manning? couldn't they have been manning?