must jam
Regular verb: jam - jammed- jammed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must jam
you must jam
she must jam
we must jam
you must jam
they must jam 	I must be jamming
you must be jamming
she must be jamming
we must be jamming
you must be jamming
they must be jamming	I must have jammed
you must have jammed
she must have jammed
we must have jammed
you must have jammed
they must have jammed	I must have been jamming
you must have been jamming
she must have been jamming
we must have been jamming
you must have been jamming
they must have been jamming	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not jam
you must not jam
she must not jam
we must not jam
you must not jam
they must not jam 	I must not be jamming
you must not be jamming
she must not be jamming
we must not be jamming
you must not be jamming
they must not be jamming	I must not have jammed
you must not have jammed
she must not have jammed
we must not have jammed
you must not have jammed
they must not have jammed	I must not have been jamming
you must not have been jamming
she must not have been jamming
we must not have been jamming
you must not have been jamming
they must not have been jamming	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I jam?
must you jam?
must she jam?
must we jam?
must you jam?
must they jam? 	must I be jamming?
must you be jamming?
must she be jamming?
must we be jamming?
must you be jamming?
must they be jamming? 	must I have jammed?
must you have jammed?
must she have jammed?
must we have jammed?
must you have jammed?
must they have jammed? 	must I have been jamming?
must you have been jamming?
must she have been jamming?
must we have been jamming?
must you have been jamming?
must they have been jamming? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not jam?
must you not jam?
must she not jam?
must we not jam?
must you not jam?
must they not jam? 	must I not be jamming?
must you not be jamming?
must she not be jamming?
must we not be jamming?
must you not be jamming?
must they not be jamming? 	must I not have jammed?
must you not have jammed?
must she not have jammed?
must we not have jammed?
must you not have jammed?
must they not have jammed? 	must I not have been jamming?
must you not have been jamming?
must she not have been jamming?
must we not have been jamming?
must you not have been jamming?
must they not have been jamming?