English verb conjugation
MUST PEN

Regular verb: pen - penned - penned

Affirmation

Simple form	V-ing form
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
Perfect	V-ing perfect
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

Negation

Simple form	V-ing form
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
Perfect	V-ing perfect
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

Interrogative form

Simple form	V-ing form
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?
Perfect	V-ing perfect
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?

Interro-negative form

Simple form	V-ing form
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?
Perfect	V-ing perfect
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?