must know
Verbo irregular: know - knew- known

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must know
you must know
he must know
we must know
you must know
they must know 	I must be knowing
you must be knowing
he must be knowing
we must be knowing
you must be knowing
they must be knowing	I must have known
you must have known
he must have known
we must have known
you must have known
they must have known	I must have been knowing
you must have been knowing
he must have been knowing
we must have been knowing
you must have been knowing
they must have been knowing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't know
you mustn't know
he mustn't know
we mustn't know
you mustn't know
they mustn't know 	I mustn't be knowing
you mustn't be knowing
he mustn't be knowing
we mustn't be knowing
you mustn't be knowing
they mustn't be knowing	I mustn't have known
you mustn't have known
he mustn't have known
we mustn't have known
you mustn't have known
they mustn't have known	I mustn't have been knowing
you mustn't have been knowing
he mustn't have been knowing
we mustn't have been knowing
you mustn't have been knowing
they mustn't have been knowing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I know?
must you know?
must he know?
must we know?
must you know?
must they know? 	must I be knowing?
must you be knowing?
must he be knowing?
must we be knowing?
must you be knowing?
must they be knowing? 	must I have known?
must you have known?
must he have known?
must we have known?
must you have known?
must they have known? 	must I have been knowing?
must you have been knowing?
must he have been knowing?
must we have been knowing?
must you have been knowing?
must they have been knowing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I know?
mustn't you know?
mustn't he know?
mustn't we know?
mustn't you know?
mustn't they know? 	mustn't I be knowing?
mustn't you be knowing?
mustn't he be knowing?
mustn't we be knowing?
mustn't you be knowing?
mustn't they be knowing? 	mustn't I have known?
mustn't you have known?
mustn't he have known?
mustn't we have known?
mustn't you have known?
mustn't they have known? 	mustn't I have been knowing?
mustn't you have been knowing?
mustn't he have been knowing?
mustn't we have been knowing?
mustn't you have been knowing?
mustn't they have been knowing?