English verb conjugation
MUST EARN

Regular verb: earn - earned - earned

Affirmation

Simple form	V-ing form
I must earn you must earn she must earn we must earn you must earn they must earn	I must be earning you must be earning she must be earning we must be earning you must be earning they must be earning
Perfect	V-ing perfect
I must have earned you must have earned she must have earned we must have earned you must have earned they must have earned	I must have been earning you must have been earning she must have been earning we must have been earning you must have been earning they must have been earning

Negation

Simple form	V-ing form
I must not earn you must not earn she must not earn we must not earn you must not earn they must not earn	I must not be earning you must not be earning she must not be earning we must not be earning you must not be earning they must not be earning
Perfect	V-ing perfect
I must not have earned you must not have earned she must not have earned we must not have earned you must not have earned they must not have earned	I must not have been earning you must not have been earning she must not have been earning we must not have been earning you must not have been earning they must not have been earning

Interrogative form

Simple form	V-ing form
must I earn? must you earn? must she earn? must we earn? must you earn? must they earn?	must I be earning? must you be earning? must she be earning? must we be earning? must you be earning? must they be earning?
Perfect	V-ing perfect
must I have earned? must you have earned? must she have earned? must we have earned? must you have earned? must they have earned?	must I have been earning? must you have been earning? must she have been earning? must we have been earning? must you have been earning? must they have been earning?

Interro-negative form

Simple form	V-ing form
must I not earn? must you not earn? must she not earn? must we not earn? must you not earn? must they not earn?	must I not be earning? must you not be earning? must she not be earning? must we not be earning? must you not be earning? must they not be earning?
Perfect	V-ing perfect
must I not have earned? must you not have earned? must she not have earned? must we not have earned? must you not have earned? must they not have earned?	must I not have been earning? must you not have been earning? must she not have been earning? must we not have been earning? must you not have been earning? must they not have been earning?