English verb conjugation
MUST BURN

Regular verb: burn - burned - burned

Affirmation

Simple form	V-ing form
I must burn you must burn she must burn we must burn you must burn they must burn	I must be burning you must be burning she must be burning we must be burning you must be burning they must be burning
Perfect	V-ing perfect
I must have burned you must have burned she must have burned we must have burned you must have burned they must have burned	I must have been burning you must have been burning she must have been burning we must have been burning you must have been burning they must have been burning

Negation

Simple form	V-ing form
I must not burn you must not burn she must not burn we must not burn you must not burn they must not burn	I must not be burning you must not be burning she must not be burning we must not be burning you must not be burning they must not be burning
Perfect	V-ing perfect
I must not have burned you must not have burned she must not have burned we must not have burned you must not have burned they must not have burned	I must not have been burning you must not have been burning she must not have been burning we must not have been burning you must not have been burning they must not have been burning

Interrogative form

Simple form	V-ing form
must I burn? must you burn? must she burn? must we burn? must you burn? must they burn?	must I be burning? must you be burning? must she be burning? must we be burning? must you be burning? must they be burning?
Perfect	V-ing perfect
must I have burned? must you have burned? must she have burned? must we have burned? must you have burned? must they have burned?	must I have been burning? must you have been burning? must she have been burning? must we have been burning? must you have been burning? must they have been burning?

Interro-negative form

Simple form	V-ing form
must I not burn? must you not burn? must she not burn? must we not burn? must you not burn? must they not burn?	must I not be burning? must you not be burning? must she not be burning? must we not be burning? must you not be burning? must they not be burning?
Perfect	V-ing perfect
must I not have burned? must you not have burned? must she not have burned? must we not have burned? must you not have burned? must they not have burned?	must I not have been burning? must you not have been burning? must she not have been burning? must we not have been burning? must you not have been burning? must they not have been burning?