I could prefer you could prefer he could prefer we could prefer you could prefer they could prefer
V-ing form
I could be preferring you could be preferring he could be preferring we could be preferring you could be preferring they could be preferring
Perfect
I could have preferred you could have preferred he could have preferred we could have preferred you could have preferred they could have preferred
V-ing perfect
I could have been preferring you could have been preferring he could have been preferring we could have been preferring you could have been preferring they could have been preferring
Negation
Simple form
I could not prefer you could not prefer he could not prefer we could not prefer you could not prefer they could not prefer
V-ing form
I could not be preferring you could not be preferring he could not be preferring we could not be preferring you could not be preferring they could not be preferring
Perfect
I could not have preferred you could not have preferred he could not have preferred we could not have preferred you could not have preferred they could not have preferred
V-ing perfect
I could not have been preferring you could not have been preferring he could not have been preferring we could not have been preferring you could not have been preferring they could not have been preferring
Interrogative form
Simple form
could I prefer? could you prefer? could he prefer? could we prefer? could you prefer? could they prefer?
V-ing form
could I be preferring? could you be preferring? could he be preferring? could we be preferring? could you be preferring? could they be preferring?
Perfect
could I have preferred? could you have preferred? could he have preferred? could we have preferred? could you have preferred? could they have preferred?
V-ing perfect
could I have been preferring? could you have been preferring? could he have been preferring? could we have been preferring? could you have been preferring? could they have been preferring?
Interro-negative form
Simple form
could I not prefer? could you not prefer? could he not prefer? could we not prefer? could you not prefer? could they not prefer?
V-ing form
could I not be preferring? could you not be preferring? could he not be preferring? could we not be preferring? could you not be preferring? could they not be preferring?
Perfect
could I not have preferred? could you not have preferred? could he not have preferred? could we not have preferred? could you not have preferred? could they not have preferred?
V-ing perfect
could I not have been preferring? could you not have been preferring? could he not have been preferring? could we not have been preferring? could you not have been preferring? could they not have been preferring?