English verb conjugation
MUST GAS

Regular verb: gas - gassed - gassed

Affirmation

Simple form	V-ing form
I must gas you must gas he must gas we must gas you must gas they must gas	I must be gassing you must be gassing he must be gassing we must be gassing you must be gassing they must be gassing
Perfect	V-ing perfect
I must have gassed you must have gassed he must have gassed we must have gassed you must have gassed they must have gassed	I must have been gassing you must have been gassing he must have been gassing we must have been gassing you must have been gassing they must have been gassing

Negation

Simple form	V-ing form
I must not gas you must not gas he must not gas we must not gas you must not gas they must not gas	I must not be gassing you must not be gassing he must not be gassing we must not be gassing you must not be gassing they must not be gassing
Perfect	V-ing perfect
I must not have gassed you must not have gassed he must not have gassed we must not have gassed you must not have gassed they must not have gassed	I must not have been gassing you must not have been gassing he must not have been gassing we must not have been gassing you must not have been gassing they must not have been gassing

Interrogative form

Simple form	V-ing form
must I gas? must you gas? must he gas? must we gas? must you gas? must they gas?	must I be gassing? must you be gassing? must he be gassing? must we be gassing? must you be gassing? must they be gassing?
Perfect	V-ing perfect
must I have gassed? must you have gassed? must he have gassed? must we have gassed? must you have gassed? must they have gassed?	must I have been gassing? must you have been gassing? must he have been gassing? must we have been gassing? must you have been gassing? must they have been gassing?

Interro-negative form

Simple form	V-ing form
must I not gas? must you not gas? must he not gas? must we not gas? must you not gas? must they not gas?	must I not be gassing? must you not be gassing? must he not be gassing? must we not be gassing? must you not be gassing? must they not be gassing?
Perfect	V-ing perfect
must I not have gassed? must you not have gassed? must he not have gassed? must we not have gassed? must you not have gassed? must they not have gassed?	must I not have been gassing? must you not have been gassing? must he not have been gassing? must we not have been gassing? must you not have been gassing? must they not have been gassing?