must piffle
Regular verb: piffle - piffled- piffled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must piffle
you must piffle
he must piffle
we must piffle
you must piffle
they must piffle 	I must be piffling
you must be piffling
he must be piffling
we must be piffling
you must be piffling
they must be piffling	I must have piffled
you must have piffled
he must have piffled
we must have piffled
you must have piffled
they must have piffled	I must have been piffling
you must have been piffling
he must have been piffling
we must have been piffling
you must have been piffling
they must have been piffling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't piffle
you mustn't piffle
he mustn't piffle
we mustn't piffle
you mustn't piffle
they mustn't piffle 	I mustn't be piffling
you mustn't be piffling
he mustn't be piffling
we mustn't be piffling
you mustn't be piffling
they mustn't be piffling	I mustn't have piffled
you mustn't have piffled
he mustn't have piffled
we mustn't have piffled
you mustn't have piffled
they mustn't have piffled	I mustn't have been piffling
you mustn't have been piffling
he mustn't have been piffling
we mustn't have been piffling
you mustn't have been piffling
they mustn't have been piffling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I piffle?
must you piffle?
must he piffle?
must we piffle?
must you piffle?
must they piffle? 	must I be piffling?
must you be piffling?
must he be piffling?
must we be piffling?
must you be piffling?
must they be piffling? 	must I have piffled?
must you have piffled?
must he have piffled?
must we have piffled?
must you have piffled?
must they have piffled? 	must I have been piffling?
must you have been piffling?
must he have been piffling?
must we have been piffling?
must you have been piffling?
must they have been piffling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I piffle?
mustn't you piffle?
mustn't he piffle?
mustn't we piffle?
mustn't you piffle?
mustn't they piffle? 	mustn't I be piffling?
mustn't you be piffling?
mustn't he be piffling?
mustn't we be piffling?
mustn't you be piffling?
mustn't they be piffling? 	mustn't I have piffled?
mustn't you have piffled?
mustn't he have piffled?
mustn't we have piffled?
mustn't you have piffled?
mustn't they have piffled? 	mustn't I have been piffling?
mustn't you have been piffling?
mustn't he have been piffling?
mustn't we have been piffling?
mustn't you have been piffling?
mustn't they have been piffling?