I could prosper you could prosper she could prosper we could prosper you could prosper they could prosper
V-ing form
I could be prospering you could be prospering she could be prospering we could be prospering you could be prospering they could be prospering
Perfect
I could have prospered you could have prospered she could have prospered we could have prospered you could have prospered they could have prospered
V-ing perfect
I could have been prospering you could have been prospering she could have been prospering we could have been prospering you could have been prospering they could have been prospering
Negation
Simple form
I could not prosper you could not prosper she could not prosper we could not prosper you could not prosper they could not prosper
V-ing form
I could not be prospering you could not be prospering she could not be prospering we could not be prospering you could not be prospering they could not be prospering
Perfect
I could not have prospered you could not have prospered she could not have prospered we could not have prospered you could not have prospered they could not have prospered
V-ing perfect
I could not have been prospering you could not have been prospering she could not have been prospering we could not have been prospering you could not have been prospering they could not have been prospering
Interrogative form
Simple form
could I prosper? could you prosper? could she prosper? could we prosper? could you prosper? could they prosper?
V-ing form
could I be prospering? could you be prospering? could she be prospering? could we be prospering? could you be prospering? could they be prospering?
Perfect
could I have prospered? could you have prospered? could she have prospered? could we have prospered? could you have prospered? could they have prospered?
V-ing perfect
could I have been prospering? could you have been prospering? could she have been prospering? could we have been prospering? could you have been prospering? could they have been prospering?
Interro-negative form
Simple form
could I not prosper? could you not prosper? could she not prosper? could we not prosper? could you not prosper? could they not prosper?
V-ing form
could I not be prospering? could you not be prospering? could she not be prospering? could we not be prospering? could you not be prospering? could they not be prospering?
Perfect
could I not have prospered? could you not have prospered? could she not have prospered? could we not have prospered? could you not have prospered? could they not have prospered?
V-ing perfect
could I not have been prospering? could you not have been prospering? could she not have been prospering? could we not have been prospering? could you not have been prospering? could they not have been prospering?