Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I must gasser you must gasser she must gasser we must gasser you must gasser they must gasser
V-ing form
I must be gassering you must be gassering she must be gassering we must be gassering you must be gassering they must be gassering
Perfect
I must have gassered you must have gassered she must have gassered we must have gassered you must have gassered they must have gassered
V-ing perfect
I must have been gassering you must have been gassering she must have been gassering we must have been gassering you must have been gassering they must have been gassering
Negation
Simple form
I must not gasser you must not gasser she must not gasser we must not gasser you must not gasser they must not gasser
V-ing form
I must not be gassering you must not be gassering she must not be gassering we must not be gassering you must not be gassering they must not be gassering
Perfect
I must not have gassered you must not have gassered she must not have gassered we must not have gassered you must not have gassered they must not have gassered
V-ing perfect
I must not have been gassering you must not have been gassering she must not have been gassering we must not have been gassering you must not have been gassering they must not have been gassering
Interrogative form
Simple form
must I gasser? must you gasser? must she gasser? must we gasser? must you gasser? must they gasser?
V-ing form
must I be gassering? must you be gassering? must she be gassering? must we be gassering? must you be gassering? must they be gassering?
Perfect
must I have gassered? must you have gassered? must she have gassered? must we have gassered? must you have gassered? must they have gassered?
V-ing perfect
must I have been gassering? must you have been gassering? must she have been gassering? must we have been gassering? must you have been gassering? must they have been gassering?
Interro-negative form
Simple form
must I not gasser? must you not gasser? must she not gasser? must we not gasser? must you not gasser? must they not gasser?
V-ing form
must I not be gassering? must you not be gassering? must she not be gassering? must we not be gassering? must you not be gassering? must they not be gassering?
Perfect
must I not have gassered? must you not have gassered? must she not have gassered? must we not have gassered? must you not have gassered? must they not have gassered?
V-ing perfect
must I not have been gassering? must you not have been gassering? must she not have been gassering? must we not have been gassering? must you not have been gassering? must they not have been gassering?