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