English verb conjugation
MUST FORTIFY

Regular verb: fortify - fortified - fortified

Affirmation

Simple form	V-ing form
I must fortify you must fortify she must fortify we must fortify you must fortify they must fortify	I must be fortifying you must be fortifying she must be fortifying we must be fortifying you must be fortifying they must be fortifying
Perfect	V-ing perfect
I must have fortified you must have fortified she must have fortified we must have fortified you must have fortified they must have fortified	I must have been fortifying you must have been fortifying she must have been fortifying we must have been fortifying you must have been fortifying they must have been fortifying

Negation

Simple form	V-ing form
I must not fortify you must not fortify she must not fortify we must not fortify you must not fortify they must not fortify	I must not be fortifying you must not be fortifying she must not be fortifying we must not be fortifying you must not be fortifying they must not be fortifying
Perfect	V-ing perfect
I must not have fortified you must not have fortified she must not have fortified we must not have fortified you must not have fortified they must not have fortified	I must not have been fortifying you must not have been fortifying she must not have been fortifying we must not have been fortifying you must not have been fortifying they must not have been fortifying

Interrogative form

Simple form	V-ing form
must I fortify? must you fortify? must she fortify? must we fortify? must you fortify? must they fortify?	must I be fortifying? must you be fortifying? must she be fortifying? must we be fortifying? must you be fortifying? must they be fortifying?
Perfect	V-ing perfect
must I have fortified? must you have fortified? must she have fortified? must we have fortified? must you have fortified? must they have fortified?	must I have been fortifying? must you have been fortifying? must she have been fortifying? must we have been fortifying? must you have been fortifying? must they have been fortifying?

Interro-negative form

Simple form	V-ing form
must I not fortify? must you not fortify? must she not fortify? must we not fortify? must you not fortify? must they not fortify?	must I not be fortifying? must you not be fortifying? must she not be fortifying? must we not be fortifying? must you not be fortifying? must they not be fortifying?
Perfect	V-ing perfect
must I not have fortified? must you not have fortified? must she not have fortified? must we not have fortified? must you not have fortified? must they not have fortified?	must I not have been fortifying? must you not have been fortifying? must she not have been fortifying? must we not have been fortifying? must you not have been fortifying? must they not have been fortifying?