English verb conjugation
MUST STALE

Regular verb: stale - staled - staled

Affirmation

Simple form	V-ing form
I must stale you must stale he must stale we must stale you must stale they must stale	I must be staling you must be staling he must be staling we must be staling you must be staling they must be staling
Perfect	V-ing perfect
I must have staled you must have staled he must have staled we must have staled you must have staled they must have staled	I must have been staling you must have been staling he must have been staling we must have been staling you must have been staling they must have been staling

Negation

Simple form	V-ing form
I mustn't stale you mustn't stale he mustn't stale we mustn't stale you mustn't stale they mustn't stale	I mustn't be staling you mustn't be staling he mustn't be staling we mustn't be staling you mustn't be staling they mustn't be staling
Perfect	V-ing perfect
I mustn't have staled you mustn't have staled he mustn't have staled we mustn't have staled you mustn't have staled they mustn't have staled	I mustn't have been staling you mustn't have been staling he mustn't have been staling we mustn't have been staling you mustn't have been staling they mustn't have been staling

Interrogative form

Simple form	V-ing form
must I stale? must you stale? must he stale? must we stale? must you stale? must they stale?	must I be staling? must you be staling? must he be staling? must we be staling? must you be staling? must they be staling?
Perfect	V-ing perfect
must I have staled? must you have staled? must he have staled? must we have staled? must you have staled? must they have staled?	must I have been staling? must you have been staling? must he have been staling? must we have been staling? must you have been staling? must they have been staling?

Interro-negative form

Simple form	V-ing form
mustn't I stale? mustn't you stale? mustn't he stale? mustn't we stale? mustn't you stale? mustn't they stale?	mustn't I be staling? mustn't you be staling? mustn't he be staling? mustn't we be staling? mustn't you be staling? mustn't they be staling?
Perfect	V-ing perfect
mustn't I have staled? mustn't you have staled? mustn't he have staled? mustn't we have staled? mustn't you have staled? mustn't they have staled?	mustn't I have been staling? mustn't you have been staling? mustn't he have been staling? mustn't we have been staling? mustn't you have been staling? mustn't they have been staling?