must smother
Regular verb: smother - smothered- smothered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must smother
you must smother
he must smother
we must smother
you must smother
they must smother 	I must be smothering
you must be smothering
he must be smothering
we must be smothering
you must be smothering
they must be smothering	I must have smothered
you must have smothered
he must have smothered
we must have smothered
you must have smothered
they must have smothered	I must have been smothering
you must have been smothering
he must have been smothering
we must have been smothering
you must have been smothering
they must have been smothering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't smother
you mustn't smother
he mustn't smother
we mustn't smother
you mustn't smother
they mustn't smother 	I mustn't be smothering
you mustn't be smothering
he mustn't be smothering
we mustn't be smothering
you mustn't be smothering
they mustn't be smothering	I mustn't have smothered
you mustn't have smothered
he mustn't have smothered
we mustn't have smothered
you mustn't have smothered
they mustn't have smothered	I mustn't have been smothering
you mustn't have been smothering
he mustn't have been smothering
we mustn't have been smothering
you mustn't have been smothering
they mustn't have been smothering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I smother?
must you smother?
must he smother?
must we smother?
must you smother?
must they smother? 	must I be smothering?
must you be smothering?
must he be smothering?
must we be smothering?
must you be smothering?
must they be smothering? 	must I have smothered?
must you have smothered?
must he have smothered?
must we have smothered?
must you have smothered?
must they have smothered? 	must I have been smothering?
must you have been smothering?
must he have been smothering?
must we have been smothering?
must you have been smothering?
must they have been smothering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I smother?
mustn't you smother?
mustn't he smother?
mustn't we smother?
mustn't you smother?
mustn't they smother? 	mustn't I be smothering?
mustn't you be smothering?
mustn't he be smothering?
mustn't we be smothering?
mustn't you be smothering?
mustn't they be smothering? 	mustn't I have smothered?
mustn't you have smothered?
mustn't he have smothered?
mustn't we have smothered?
mustn't you have smothered?
mustn't they have smothered? 	mustn't I have been smothering?
mustn't you have been smothering?
mustn't he have been smothering?
mustn't we have been smothering?
mustn't you have been smothering?
mustn't they have been smothering?