must sack
Regular verb: sack - sacked- sacked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must sack
you must sack
she must sack
we must sack
you must sack
they must sack 	I must be sacking
you must be sacking
she must be sacking
we must be sacking
you must be sacking
they must be sacking	I must have sacked
you must have sacked
she must have sacked
we must have sacked
you must have sacked
they must have sacked	I must have been sacking
you must have been sacking
she must have been sacking
we must have been sacking
you must have been sacking
they must have been sacking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not sack
you must not sack
she must not sack
we must not sack
you must not sack
they must not sack 	I must not be sacking
you must not be sacking
she must not be sacking
we must not be sacking
you must not be sacking
they must not be sacking	I must not have sacked
you must not have sacked
she must not have sacked
we must not have sacked
you must not have sacked
they must not have sacked	I must not have been sacking
you must not have been sacking
she must not have been sacking
we must not have been sacking
you must not have been sacking
they must not have been sacking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I sack?
must you sack?
must she sack?
must we sack?
must you sack?
must they sack? 	must I be sacking?
must you be sacking?
must she be sacking?
must we be sacking?
must you be sacking?
must they be sacking? 	must I have sacked?
must you have sacked?
must she have sacked?
must we have sacked?
must you have sacked?
must they have sacked? 	must I have been sacking?
must you have been sacking?
must she have been sacking?
must we have been sacking?
must you have been sacking?
must they have been sacking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not sack?
must you not sack?
must she not sack?
must we not sack?
must you not sack?
must they not sack? 	must I not be sacking?
must you not be sacking?
must she not be sacking?
must we not be sacking?
must you not be sacking?
must they not be sacking? 	must I not have sacked?
must you not have sacked?
must she not have sacked?
must we not have sacked?
must you not have sacked?
must they not have sacked? 	must I not have been sacking?
must you not have been sacking?
must she not have been sacking?
must we not have been sacking?
must you not have been sacking?
must they not have been sacking?