English verb conjugation
MUST DUMB

Regular verb: dumb - dumbed - dumbed

Affirmation

Simple form	V-ing form
I must dumb you must dumb he must dumb we must dumb you must dumb they must dumb	I must be dumbing you must be dumbing he must be dumbing we must be dumbing you must be dumbing they must be dumbing
Perfect	V-ing perfect
I must have dumbed you must have dumbed he must have dumbed we must have dumbed you must have dumbed they must have dumbed	I must have been dumbing you must have been dumbing he must have been dumbing we must have been dumbing you must have been dumbing they must have been dumbing

Negation

Simple form	V-ing form
I must not dumb you must not dumb he must not dumb we must not dumb you must not dumb they must not dumb	I must not be dumbing you must not be dumbing he must not be dumbing we must not be dumbing you must not be dumbing they must not be dumbing
Perfect	V-ing perfect
I must not have dumbed you must not have dumbed he must not have dumbed we must not have dumbed you must not have dumbed they must not have dumbed	I must not have been dumbing you must not have been dumbing he must not have been dumbing we must not have been dumbing you must not have been dumbing they must not have been dumbing

Interrogative form

Simple form	V-ing form
must I dumb? must you dumb? must he dumb? must we dumb? must you dumb? must they dumb?	must I be dumbing? must you be dumbing? must he be dumbing? must we be dumbing? must you be dumbing? must they be dumbing?
Perfect	V-ing perfect
must I have dumbed? must you have dumbed? must he have dumbed? must we have dumbed? must you have dumbed? must they have dumbed?	must I have been dumbing? must you have been dumbing? must he have been dumbing? must we have been dumbing? must you have been dumbing? must they have been dumbing?

Interro-negative form

Simple form	V-ing form
must I not dumb? must you not dumb? must he not dumb? must we not dumb? must you not dumb? must they not dumb?	must I not be dumbing? must you not be dumbing? must he not be dumbing? must we not be dumbing? must you not be dumbing? must they not be dumbing?
Perfect	V-ing perfect
must I not have dumbed? must you not have dumbed? must he not have dumbed? must we not have dumbed? must you not have dumbed? must they not have dumbed?	must I not have been dumbing? must you not have been dumbing? must he not have been dumbing? must we not have been dumbing? must you not have been dumbing? must they not have been dumbing?