English verb conjugation
MUST SHEATHE

Regular verb: sheathe - sheathed - sheathed

Affirmation

Simple form	V-ing form
I must sheathe you must sheathe she must sheathe we must sheathe you must sheathe they must sheathe	I must be sheathing you must be sheathing she must be sheathing we must be sheathing you must be sheathing they must be sheathing
Perfect	V-ing perfect
I must have sheathed you must have sheathed she must have sheathed we must have sheathed you must have sheathed they must have sheathed	I must have been sheathing you must have been sheathing she must have been sheathing we must have been sheathing you must have been sheathing they must have been sheathing

Negation

Simple form	V-ing form
I must not sheathe you must not sheathe she must not sheathe we must not sheathe you must not sheathe they must not sheathe	I must not be sheathing you must not be sheathing she must not be sheathing we must not be sheathing you must not be sheathing they must not be sheathing
Perfect	V-ing perfect
I must not have sheathed you must not have sheathed she must not have sheathed we must not have sheathed you must not have sheathed they must not have sheathed	I must not have been sheathing you must not have been sheathing she must not have been sheathing we must not have been sheathing you must not have been sheathing they must not have been sheathing

Interrogative form

Simple form	V-ing form
must I sheathe? must you sheathe? must she sheathe? must we sheathe? must you sheathe? must they sheathe?	must I be sheathing? must you be sheathing? must she be sheathing? must we be sheathing? must you be sheathing? must they be sheathing?
Perfect	V-ing perfect
must I have sheathed? must you have sheathed? must she have sheathed? must we have sheathed? must you have sheathed? must they have sheathed?	must I have been sheathing? must you have been sheathing? must she have been sheathing? must we have been sheathing? must you have been sheathing? must they have been sheathing?

Interro-negative form

Simple form	V-ing form
must I not sheathe? must you not sheathe? must she not sheathe? must we not sheathe? must you not sheathe? must they not sheathe?	must I not be sheathing? must you not be sheathing? must she not be sheathing? must we not be sheathing? must you not be sheathing? must they not be sheathing?
Perfect	V-ing perfect
must I not have sheathed? must you not have sheathed? must she not have sheathed? must we not have sheathed? must you not have sheathed? must they not have sheathed?	must I not have been sheathing? must you not have been sheathing? must she not have been sheathing? must we not have been sheathing? must you not have been sheathing? must they not have been sheathing?