English verb conjugation
MUST SACK

Regular verb: sack - sacked - sacked

Affirmation

Simple form	V-ing form
I must sack you must sack he must sack we must sack you must sack they must sack	I must be sacking you must be sacking he 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 he 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 he 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 mustn't sack you mustn't sack he mustn't sack we mustn't sack you mustn't sack they mustn't sack	I mustn't be sacking you mustn't be sacking he mustn't be sacking we mustn't be sacking you mustn't be sacking they mustn't be sacking
Perfect	V-ing perfect
I mustn't have sacked you mustn't have sacked he mustn't have sacked we mustn't have sacked you mustn't have sacked they mustn't have sacked	I mustn't have been sacking you mustn't have been sacking he mustn't have been sacking we mustn't have been sacking you mustn't have been sacking they mustn't have been sacking

Interrogative form

Simple form	V-ing form
must I sack? must you sack? must he sack? must we sack? must you sack? must they sack?	must I be sacking? must you be sacking? must he 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 he 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 he 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
mustn't I sack? mustn't you sack? mustn't he sack? mustn't we sack? mustn't you sack? mustn't they sack?	mustn't I be sacking? mustn't you be sacking? mustn't he be sacking? mustn't we be sacking? mustn't you be sacking? mustn't they be sacking?
Perfect	V-ing perfect
mustn't I have sacked? mustn't you have sacked? mustn't he have sacked? mustn't we have sacked? mustn't you have sacked? mustn't they have sacked?	mustn't I have been sacking? mustn't you have been sacking? mustn't he have been sacking? mustn't we have been sacking? mustn't you have been sacking? mustn't they have been sacking?