English verb conjugation
MUST PREFER

Regular verb: prefer - preferred - preferred

Affirmation

Simple form	V-ing form
I must prefer you must prefer he must prefer we must prefer you must prefer they must prefer	I must be preferring you must be preferring he must be preferring we must be preferring you must be preferring they must be preferring
Perfect	V-ing perfect
I must have preferred you must have preferred he must have preferred we must have preferred you must have preferred they must have preferred	I must have been preferring you must have been preferring he must have been preferring we must have been preferring you must have been preferring they must have been preferring

Negation

Simple form	V-ing form
I mustn't prefer you mustn't prefer he mustn't prefer we mustn't prefer you mustn't prefer they mustn't prefer	I mustn't be preferring you mustn't be preferring he mustn't be preferring we mustn't be preferring you mustn't be preferring they mustn't be preferring
Perfect	V-ing perfect
I mustn't have preferred you mustn't have preferred he mustn't have preferred we mustn't have preferred you mustn't have preferred they mustn't have preferred	I mustn't have been preferring you mustn't have been preferring he mustn't have been preferring we mustn't have been preferring you mustn't have been preferring they mustn't have been preferring

Interrogative form

Simple form	V-ing form
must I prefer? must you prefer? must he prefer? must we prefer? must you prefer? must they prefer?	must I be preferring? must you be preferring? must he be preferring? must we be preferring? must you be preferring? must they be preferring?
Perfect	V-ing perfect
must I have preferred? must you have preferred? must he have preferred? must we have preferred? must you have preferred? must they have preferred?	must I have been preferring? must you have been preferring? must he have been preferring? must we have been preferring? must you have been preferring? must they have been preferring?

Interro-negative form

Simple form	V-ing form
mustn't I prefer? mustn't you prefer? mustn't he prefer? mustn't we prefer? mustn't you prefer? mustn't they prefer?	mustn't I be preferring? mustn't you be preferring? mustn't he be preferring? mustn't we be preferring? mustn't you be preferring? mustn't they be preferring?
Perfect	V-ing perfect
mustn't I have preferred? mustn't you have preferred? mustn't he have preferred? mustn't we have preferred? mustn't you have preferred? mustn't they have preferred?	mustn't I have been preferring? mustn't you have been preferring? mustn't he have been preferring? mustn't we have been preferring? mustn't you have been preferring? mustn't they have been preferring?