must jack
Regular verb: jack - jacked- jacked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must jack
you must jack
she must jack
we must jack
you must jack
they must jack 	I must be jacking
you must be jacking
she must be jacking
we must be jacking
you must be jacking
they must be jacking	I must have jacked
you must have jacked
she must have jacked
we must have jacked
you must have jacked
they must have jacked	I must have been jacking
you must have been jacking
she must have been jacking
we must have been jacking
you must have been jacking
they must have been jacking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't jack
you mustn't jack
she mustn't jack
we mustn't jack
you mustn't jack
they mustn't jack 	I mustn't be jacking
you mustn't be jacking
she mustn't be jacking
we mustn't be jacking
you mustn't be jacking
they mustn't be jacking	I mustn't have jacked
you mustn't have jacked
she mustn't have jacked
we mustn't have jacked
you mustn't have jacked
they mustn't have jacked	I mustn't have been jacking
you mustn't have been jacking
she mustn't have been jacking
we mustn't have been jacking
you mustn't have been jacking
they mustn't have been jacking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I jack?
must you jack?
must she jack?
must we jack?
must you jack?
must they jack? 	must I be jacking?
must you be jacking?
must she be jacking?
must we be jacking?
must you be jacking?
must they be jacking? 	must I have jacked?
must you have jacked?
must she have jacked?
must we have jacked?
must you have jacked?
must they have jacked? 	must I have been jacking?
must you have been jacking?
must she have been jacking?
must we have been jacking?
must you have been jacking?
must they have been jacking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I jack?
mustn't you jack?
mustn't she jack?
mustn't we jack?
mustn't you jack?
mustn't they jack? 	mustn't I be jacking?
mustn't you be jacking?
mustn't she be jacking?
mustn't we be jacking?
mustn't you be jacking?
mustn't they be jacking? 	mustn't I have jacked?
mustn't you have jacked?
mustn't she have jacked?
mustn't we have jacked?
mustn't you have jacked?
mustn't they have jacked? 	mustn't I have been jacking?
mustn't you have been jacking?
mustn't she have been jacking?
mustn't we have been jacking?
mustn't you have been jacking?
mustn't they have been jacking?