must unmask
Regular verb: unmask - unmasked- unmasked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must unmask
you must unmask
he must unmask
we must unmask
you must unmask
they must unmask 	I must be unmasking
you must be unmasking
he must be unmasking
we must be unmasking
you must be unmasking
they must be unmasking	I must have unmasked
you must have unmasked
he must have unmasked
we must have unmasked
you must have unmasked
they must have unmasked	I must have been unmasking
you must have been unmasking
he must have been unmasking
we must have been unmasking
you must have been unmasking
they must have been unmasking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't unmask
you mustn't unmask
he mustn't unmask
we mustn't unmask
you mustn't unmask
they mustn't unmask 	I mustn't be unmasking
you mustn't be unmasking
he mustn't be unmasking
we mustn't be unmasking
you mustn't be unmasking
they mustn't be unmasking	I mustn't have unmasked
you mustn't have unmasked
he mustn't have unmasked
we mustn't have unmasked
you mustn't have unmasked
they mustn't have unmasked	I mustn't have been unmasking
you mustn't have been unmasking
he mustn't have been unmasking
we mustn't have been unmasking
you mustn't have been unmasking
they mustn't have been unmasking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I unmask?
must you unmask?
must he unmask?
must we unmask?
must you unmask?
must they unmask? 	must I be unmasking?
must you be unmasking?
must he be unmasking?
must we be unmasking?
must you be unmasking?
must they be unmasking? 	must I have unmasked?
must you have unmasked?
must he have unmasked?
must we have unmasked?
must you have unmasked?
must they have unmasked? 	must I have been unmasking?
must you have been unmasking?
must he have been unmasking?
must we have been unmasking?
must you have been unmasking?
must they have been unmasking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I unmask?
mustn't you unmask?
mustn't he unmask?
mustn't we unmask?
mustn't you unmask?
mustn't they unmask? 	mustn't I be unmasking?
mustn't you be unmasking?
mustn't he be unmasking?
mustn't we be unmasking?
mustn't you be unmasking?
mustn't they be unmasking? 	mustn't I have unmasked?
mustn't you have unmasked?
mustn't he have unmasked?
mustn't we have unmasked?
mustn't you have unmasked?
mustn't they have unmasked? 	mustn't I have been unmasking?
mustn't you have been unmasking?
mustn't he have been unmasking?
mustn't we have been unmasking?
mustn't you have been unmasking?
mustn't they have been unmasking?