English verb conjugation
MUST STAIN

Regular verb: stain - stained - stained

Affirmation

Simple form	V-ing form
I must stain you must stain he must stain we must stain you must stain they must stain	I must be staining you must be staining he must be staining we must be staining you must be staining they must be staining
Perfect	V-ing perfect
I must have stained you must have stained he must have stained we must have stained you must have stained they must have stained	I must have been staining you must have been staining he must have been staining we must have been staining you must have been staining they must have been staining

Negation

Simple form	V-ing form
I must not stain you must not stain he must not stain we must not stain you must not stain they must not stain	I must not be staining you must not be staining he must not be staining we must not be staining you must not be staining they must not be staining
Perfect	V-ing perfect
I must not have stained you must not have stained he must not have stained we must not have stained you must not have stained they must not have stained	I must not have been staining you must not have been staining he must not have been staining we must not have been staining you must not have been staining they must not have been staining

Interrogative form

Simple form	V-ing form
must I stain? must you stain? must he stain? must we stain? must you stain? must they stain?	must I be staining? must you be staining? must he be staining? must we be staining? must you be staining? must they be staining?
Perfect	V-ing perfect
must I have stained? must you have stained? must he have stained? must we have stained? must you have stained? must they have stained?	must I have been staining? must you have been staining? must he have been staining? must we have been staining? must you have been staining? must they have been staining?

Interro-negative form

Simple form	V-ing form
must I not stain? must you not stain? must he not stain? must we not stain? must you not stain? must they not stain?	must I not be staining? must you not be staining? must he not be staining? must we not be staining? must you not be staining? must they not be staining?
Perfect	V-ing perfect
must I not have stained? must you not have stained? must he not have stained? must we not have stained? must you not have stained? must they not have stained?	must I not have been staining? must you not have been staining? must he not have been staining? must we not have been staining? must you not have been staining? must they not have been staining?