must pen
Verbo regular: pen - penned- penned

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must pen
you must pen
he must pen
we must pen
you must pen
they must pen 	I must be penning
you must be penning
he must be penning
we must be penning
you must be penning
they must be penning	I must have penned
you must have penned
he must have penned
we must have penned
you must have penned
they must have penned	I must have been penning
you must have been penning
he must have been penning
we must have been penning
you must have been penning
they must have been penning	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't pen
you mustn't pen
he mustn't pen
we mustn't pen
you mustn't pen
they mustn't pen 	I mustn't be penning
you mustn't be penning
he mustn't be penning
we mustn't be penning
you mustn't be penning
they mustn't be penning	I mustn't have penned
you mustn't have penned
he mustn't have penned
we mustn't have penned
you mustn't have penned
they mustn't have penned	I mustn't have been penning
you mustn't have been penning
he mustn't have been penning
we mustn't have been penning
you mustn't have been penning
they mustn't have been penning	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I pen?
must you pen?
must he pen?
must we pen?
must you pen?
must they pen? 	must I be penning?
must you be penning?
must he be penning?
must we be penning?
must you be penning?
must they be penning? 	must I have penned?
must you have penned?
must he have penned?
must we have penned?
must you have penned?
must they have penned? 	must I have been penning?
must you have been penning?
must he have been penning?
must we have been penning?
must you have been penning?
must they have been penning? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I pen?
mustn't you pen?
mustn't he pen?
mustn't we pen?
mustn't you pen?
mustn't they pen? 	mustn't I be penning?
mustn't you be penning?
mustn't he be penning?
mustn't we be penning?
mustn't you be penning?
mustn't they be penning? 	mustn't I have penned?
mustn't you have penned?
mustn't he have penned?
mustn't we have penned?
mustn't you have penned?
mustn't they have penned? 	mustn't I have been penning?
mustn't you have been penning?
mustn't he have been penning?
mustn't we have been penning?
mustn't you have been penning?
mustn't they have been penning?