must prefer
Verbo regular: prefer - preferred- preferred

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
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	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	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
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	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	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
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? 	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? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
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? 	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?