must unbox
Regular verb: unbox - unboxed- unboxed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must unbox
you must unbox
he must unbox
we must unbox
you must unbox
they must unbox 	I must be unboxing
you must be unboxing
he must be unboxing
we must be unboxing
you must be unboxing
they must be unboxing	I must have unboxed
you must have unboxed
he must have unboxed
we must have unboxed
you must have unboxed
they must have unboxed	I must have been unboxing
you must have been unboxing
he must have been unboxing
we must have been unboxing
you must have been unboxing
they must have been unboxing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't unbox
you mustn't unbox
he mustn't unbox
we mustn't unbox
you mustn't unbox
they mustn't unbox 	I mustn't be unboxing
you mustn't be unboxing
he mustn't be unboxing
we mustn't be unboxing
you mustn't be unboxing
they mustn't be unboxing	I mustn't have unboxed
you mustn't have unboxed
he mustn't have unboxed
we mustn't have unboxed
you mustn't have unboxed
they mustn't have unboxed	I mustn't have been unboxing
you mustn't have been unboxing
he mustn't have been unboxing
we mustn't have been unboxing
you mustn't have been unboxing
they mustn't have been unboxing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I unbox?
must you unbox?
must he unbox?
must we unbox?
must you unbox?
must they unbox? 	must I be unboxing?
must you be unboxing?
must he be unboxing?
must we be unboxing?
must you be unboxing?
must they be unboxing? 	must I have unboxed?
must you have unboxed?
must he have unboxed?
must we have unboxed?
must you have unboxed?
must they have unboxed? 	must I have been unboxing?
must you have been unboxing?
must he have been unboxing?
must we have been unboxing?
must you have been unboxing?
must they have been unboxing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I unbox?
mustn't you unbox?
mustn't he unbox?
mustn't we unbox?
mustn't you unbox?
mustn't they unbox? 	mustn't I be unboxing?
mustn't you be unboxing?
mustn't he be unboxing?
mustn't we be unboxing?
mustn't you be unboxing?
mustn't they be unboxing? 	mustn't I have unboxed?
mustn't you have unboxed?
mustn't he have unboxed?
mustn't we have unboxed?
mustn't you have unboxed?
mustn't they have unboxed? 	mustn't I have been unboxing?
mustn't you have been unboxing?
mustn't he have been unboxing?
mustn't we have been unboxing?
mustn't you have been unboxing?
mustn't they have been unboxing?