must pen
Regular verb: pen - penned- penned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must pen
you must pen
she must pen
we must pen
you must pen
they must pen 	I must be penning
you must be penning
she must be penning
we must be penning
you must be penning
they must be penning	I must have penned
you must have penned
she 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
she 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 	Perfect 	V-ing perfect 	
I mustn't pen
you mustn't pen
she 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
she 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
she 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
she 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 	Perfect 	V-ing perfect 	
must I pen?
must you pen?
must she pen?
must we pen?
must you pen?
must they pen? 	must I be penning?
must you be penning?
must she be penning?
must we be penning?
must you be penning?
must they be penning? 	must I have penned?
must you have penned?
must she 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 she 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 	Perfect 	V-ing perfect 	
mustn't I pen?
mustn't you pen?
mustn't she 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 she 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 she 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 she have been penning?
mustn't we have been penning?
mustn't you have been penning?
mustn't they have been penning?