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 must not jack
you must not jack
she must not jack
we must not jack
you must not jack
they must not jack 	I must not be jacking
you must not be jacking
she must not be jacking
we must not be jacking
you must not be jacking
they must not be jacking	I must not have jacked
you must not have jacked
she must not have jacked
we must not have jacked
you must not have jacked
they must not have jacked	I must not have been jacking
you must not have been jacking
she must not have been jacking
we must not have been jacking
you must not have been jacking
they must not 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 	
must I not jack?
must you not jack?
must she not jack?
must we not jack?
must you not jack?
must they not jack? 	must I not be jacking?
must you not be jacking?
must she not be jacking?
must we not be jacking?
must you not be jacking?
must they not be jacking? 	must I not have jacked?
must you not have jacked?
must she not have jacked?
must we not have jacked?
must you not have jacked?
must they not have jacked? 	must I not have been jacking?
must you not have been jacking?
must she not have been jacking?
must we not have been jacking?
must you not have been jacking?
must they not have been jacking?