English verb conjugation
MUST LOCK

Regular verb: lock - locked - locked

Affirmation

Simple form	V-ing form
I must lock you must lock he must lock we must lock you must lock they must lock	I must be locking you must be locking he must be locking we must be locking you must be locking they must be locking
Perfect	V-ing perfect
I must have locked you must have locked he must have locked we must have locked you must have locked they must have locked	I must have been locking you must have been locking he must have been locking we must have been locking you must have been locking they must have been locking

Negation

Simple form	V-ing form
I must not lock you must not lock he must not lock we must not lock you must not lock they must not lock	I must not be locking you must not be locking he must not be locking we must not be locking you must not be locking they must not be locking
Perfect	V-ing perfect
I must not have locked you must not have locked he must not have locked we must not have locked you must not have locked they must not have locked	I must not have been locking you must not have been locking he must not have been locking we must not have been locking you must not have been locking they must not have been locking

Interrogative form

Simple form	V-ing form
must I lock? must you lock? must he lock? must we lock? must you lock? must they lock?	must I be locking? must you be locking? must he be locking? must we be locking? must you be locking? must they be locking?
Perfect	V-ing perfect
must I have locked? must you have locked? must he have locked? must we have locked? must you have locked? must they have locked?	must I have been locking? must you have been locking? must he have been locking? must we have been locking? must you have been locking? must they have been locking?

Interro-negative form

Simple form	V-ing form
must I not lock? must you not lock? must he not lock? must we not lock? must you not lock? must they not lock?	must I not be locking? must you not be locking? must he not be locking? must we not be locking? must you not be locking? must they not be locking?
Perfect	V-ing perfect
must I not have locked? must you not have locked? must he not have locked? must we not have locked? must you not have locked? must they not have locked?	must I not have been locking? must you not have been locking? must he not have been locking? must we not have been locking? must you not have been locking? must they not have been locking?