English verb conjugation
MUST FUNCTION

Regular verb: function - functioned - functioned

Affirmation

Simple form	V-ing form
I must function you must function he must function we must function you must function they must function	I must be functioning you must be functioning he must be functioning we must be functioning you must be functioning they must be functioning
Perfect	V-ing perfect
I must have functioned you must have functioned he must have functioned we must have functioned you must have functioned they must have functioned	I must have been functioning you must have been functioning he must have been functioning we must have been functioning you must have been functioning they must have been functioning

Negation

Simple form	V-ing form
I must not function you must not function he must not function we must not function you must not function they must not function	I must not be functioning you must not be functioning he must not be functioning we must not be functioning you must not be functioning they must not be functioning
Perfect	V-ing perfect
I must not have functioned you must not have functioned he must not have functioned we must not have functioned you must not have functioned they must not have functioned	I must not have been functioning you must not have been functioning he must not have been functioning we must not have been functioning you must not have been functioning they must not have been functioning

Interrogative form

Simple form	V-ing form
must I function? must you function? must he function? must we function? must you function? must they function?	must I be functioning? must you be functioning? must he be functioning? must we be functioning? must you be functioning? must they be functioning?
Perfect	V-ing perfect
must I have functioned? must you have functioned? must he have functioned? must we have functioned? must you have functioned? must they have functioned?	must I have been functioning? must you have been functioning? must he have been functioning? must we have been functioning? must you have been functioning? must they have been functioning?

Interro-negative form

Simple form	V-ing form
must I not function? must you not function? must he not function? must we not function? must you not function? must they not function?	must I not be functioning? must you not be functioning? must he not be functioning? must we not be functioning? must you not be functioning? must they not be functioning?
Perfect	V-ing perfect
must I not have functioned? must you not have functioned? must he not have functioned? must we not have functioned? must you not have functioned? must they not have functioned?	must I not have been functioning? must you not have been functioning? must he not have been functioning? must we not have been functioning? must you not have been functioning? must they not have been functioning?