must sulk
Regular verb: sulk - sulked- sulked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must sulk
you must sulk
he must sulk
we must sulk
you must sulk
they must sulk 	I must be sulking
you must be sulking
he must be sulking
we must be sulking
you must be sulking
they must be sulking	I must have sulked
you must have sulked
he must have sulked
we must have sulked
you must have sulked
they must have sulked	I must have been sulking
you must have been sulking
he must have been sulking
we must have been sulking
you must have been sulking
they must have been sulking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't sulk
you mustn't sulk
he mustn't sulk
we mustn't sulk
you mustn't sulk
they mustn't sulk 	I mustn't be sulking
you mustn't be sulking
he mustn't be sulking
we mustn't be sulking
you mustn't be sulking
they mustn't be sulking	I mustn't have sulked
you mustn't have sulked
he mustn't have sulked
we mustn't have sulked
you mustn't have sulked
they mustn't have sulked	I mustn't have been sulking
you mustn't have been sulking
he mustn't have been sulking
we mustn't have been sulking
you mustn't have been sulking
they mustn't have been sulking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I sulk?
must you sulk?
must he sulk?
must we sulk?
must you sulk?
must they sulk? 	must I be sulking?
must you be sulking?
must he be sulking?
must we be sulking?
must you be sulking?
must they be sulking? 	must I have sulked?
must you have sulked?
must he have sulked?
must we have sulked?
must you have sulked?
must they have sulked? 	must I have been sulking?
must you have been sulking?
must he have been sulking?
must we have been sulking?
must you have been sulking?
must they have been sulking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I sulk?
mustn't you sulk?
mustn't he sulk?
mustn't we sulk?
mustn't you sulk?
mustn't they sulk? 	mustn't I be sulking?
mustn't you be sulking?
mustn't he be sulking?
mustn't we be sulking?
mustn't you be sulking?
mustn't they be sulking? 	mustn't I have sulked?
mustn't you have sulked?
mustn't he have sulked?
mustn't we have sulked?
mustn't you have sulked?
mustn't they have sulked? 	mustn't I have been sulking?
mustn't you have been sulking?
mustn't he have been sulking?
mustn't we have been sulking?
mustn't you have been sulking?
mustn't they have been sulking?