English verb conjugation
MUST SACK

Regular verb: sack - sacked - sacked

Affirmation

Simple form	V-ing form
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
Perfect	V-ing perfect
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
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
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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?