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 must not mass you must not mass he must not mass we must not mass you must not mass they must not mass	I must not be massing you must not be massing he must not be massing we must not be massing you must not be massing they must not be massing
Perfect	V-ing perfect
I must not have massed you must not have massed he must not have massed we must not have massed you must not have massed they must not have massed	I must not have been massing you must not have been massing he must not have been massing we must not have been massing you must not have been massing they must not 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
must I not mass? must you not mass? must he not mass? must we not mass? must you not mass? must they not mass?	must I not be massing? must you not be massing? must he not be massing? must we not be massing? must you not be massing? must they not be massing?
Perfect	V-ing perfect
must I not have massed? must you not have massed? must he not have massed? must we not have massed? must you not have massed? must they not have massed?	must I not have been massing? must you not have been massing? must he not have been massing? must we not have been massing? must you not have been massing? must they not have been massing?