English verb conjugation
MUST MASS

Regular verb: mass - massed - massed

Affirmation

Simple form	V-ing form
I must mass you must mass he must mass we must mass you must mass they must mass	I must be massing you must be massing he must be massing we must be massing you must be massing they must be massing
Perfect	V-ing perfect
I must have massed you must have massed he must have massed we must have massed you must have massed they must have massed	I must have been massing you must have been massing he must have been massing we must have been massing you must have been massing they must have been massing

Negation

Simple form	V-ing form
I mustn't mass you mustn't mass he mustn't mass we mustn't mass you mustn't mass they mustn't mass	I mustn't be massing you mustn't be massing he mustn't be massing we mustn't be massing you mustn't be massing they mustn't be massing
Perfect	V-ing perfect
I mustn't have massed you mustn't have massed he mustn't have massed we mustn't have massed you mustn't have massed they mustn't have massed	I mustn't have been massing you mustn't have been massing he mustn't have been massing we mustn't have been massing you mustn't have been massing they mustn't have been massing

Interrogative form

Simple form	V-ing form
must I mass? must you mass? must he mass? must we mass? must you mass? must they mass?	must I be massing? must you be massing? must he be massing? must we be massing? must you be massing? must they be massing?
Perfect	V-ing perfect
must I have massed? must you have massed? must he have massed? must we have massed? must you have massed? must they have massed?	must I have been massing? must you have been massing? must he have been massing? must we have been massing? must you have been massing? must they have been massing?

Interro-negative form

Simple form	V-ing form
mustn't I mass? mustn't you mass? mustn't he mass? mustn't we mass? mustn't you mass? mustn't they mass?	mustn't I be massing? mustn't you be massing? mustn't he be massing? mustn't we be massing? mustn't you be massing? mustn't they be massing?
Perfect	V-ing perfect
mustn't I have massed? mustn't you have massed? mustn't he have massed? mustn't we have massed? mustn't you have massed? mustn't they have massed?	mustn't I have been massing? mustn't you have been massing? mustn't he have been massing? mustn't we have been massing? mustn't you have been massing? mustn't they have been massing?