English verb conjugation
MUST MODIFY

Regular verb: modify - modified - modified

Affirmation

Simple form	V-ing form
I must modify you must modify he must modify we must modify you must modify they must modify	I must be modifying you must be modifying he must be modifying we must be modifying you must be modifying they must be modifying
Perfect	V-ing perfect
I must have modified you must have modified he must have modified we must have modified you must have modified they must have modified	I must have been modifying you must have been modifying he must have been modifying we must have been modifying you must have been modifying they must have been modifying

Negation

Simple form	V-ing form
I must not modify you must not modify he must not modify we must not modify you must not modify they must not modify	I must not be modifying you must not be modifying he must not be modifying we must not be modifying you must not be modifying they must not be modifying
Perfect	V-ing perfect
I must not have modified you must not have modified he must not have modified we must not have modified you must not have modified they must not have modified	I must not have been modifying you must not have been modifying he must not have been modifying we must not have been modifying you must not have been modifying they must not have been modifying

Interrogative form

Simple form	V-ing form
must I modify? must you modify? must he modify? must we modify? must you modify? must they modify?	must I be modifying? must you be modifying? must he be modifying? must we be modifying? must you be modifying? must they be modifying?
Perfect	V-ing perfect
must I have modified? must you have modified? must he have modified? must we have modified? must you have modified? must they have modified?	must I have been modifying? must you have been modifying? must he have been modifying? must we have been modifying? must you have been modifying? must they have been modifying?

Interro-negative form

Simple form	V-ing form
must I not modify? must you not modify? must he not modify? must we not modify? must you not modify? must they not modify?	must I not be modifying? must you not be modifying? must he not be modifying? must we not be modifying? must you not be modifying? must they not be modifying?
Perfect	V-ing perfect
must I not have modified? must you not have modified? must he not have modified? must we not have modified? must you not have modified? must they not have modified?	must I not have been modifying? must you not have been modifying? must he not have been modifying? must we not have been modifying? must you not have been modifying? must they not have been modifying?