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 mustn't lock you mustn't lock he mustn't lock we mustn't lock you mustn't lock they mustn't lock	I mustn't be locking you mustn't be locking he mustn't be locking we mustn't be locking you mustn't be locking they mustn't be locking
Perfect	V-ing perfect
I mustn't have locked you mustn't have locked he mustn't have locked we mustn't have locked you mustn't have locked they mustn't have locked	I mustn't have been locking you mustn't have been locking he mustn't have been locking we mustn't have been locking you mustn't have been locking they mustn't 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
mustn't I lock? mustn't you lock? mustn't he lock? mustn't we lock? mustn't you lock? mustn't they lock?	mustn't I be locking? mustn't you be locking? mustn't he be locking? mustn't we be locking? mustn't you be locking? mustn't they be locking?
Perfect	V-ing perfect
mustn't I have locked? mustn't you have locked? mustn't he have locked? mustn't we have locked? mustn't you have locked? mustn't they have locked?	mustn't I have been locking? mustn't you have been locking? mustn't he have been locking? mustn't we have been locking? mustn't you have been locking? mustn't they have been locking?