English verb conjugation
MUST BRIEF

Regular verb: brief - briefed - briefed

Affirmation

Simple form	V-ing form
I must brief you must brief she must brief we must brief you must brief they must brief	I must be briefing you must be briefing she must be briefing we must be briefing you must be briefing they must be briefing
Perfect	V-ing perfect
I must have briefed you must have briefed she must have briefed we must have briefed you must have briefed they must have briefed	I must have been briefing you must have been briefing she must have been briefing we must have been briefing you must have been briefing they must have been briefing

Negation

Simple form	V-ing form
I must not brief you must not brief she must not brief we must not brief you must not brief they must not brief	I must not be briefing you must not be briefing she must not be briefing we must not be briefing you must not be briefing they must not be briefing
Perfect	V-ing perfect
I must not have briefed you must not have briefed she must not have briefed we must not have briefed you must not have briefed they must not have briefed	I must not have been briefing you must not have been briefing she must not have been briefing we must not have been briefing you must not have been briefing they must not have been briefing

Interrogative form

Simple form	V-ing form
must I brief? must you brief? must she brief? must we brief? must you brief? must they brief?	must I be briefing? must you be briefing? must she be briefing? must we be briefing? must you be briefing? must they be briefing?
Perfect	V-ing perfect
must I have briefed? must you have briefed? must she have briefed? must we have briefed? must you have briefed? must they have briefed?	must I have been briefing? must you have been briefing? must she have been briefing? must we have been briefing? must you have been briefing? must they have been briefing?

Interro-negative form

Simple form	V-ing form
must I not brief? must you not brief? must she not brief? must we not brief? must you not brief? must they not brief?	must I not be briefing? must you not be briefing? must she not be briefing? must we not be briefing? must you not be briefing? must they not be briefing?
Perfect	V-ing perfect
must I not have briefed? must you not have briefed? must she not have briefed? must we not have briefed? must you not have briefed? must they not have briefed?	must I not have been briefing? must you not have been briefing? must she not have been briefing? must we not have been briefing? must you not have been briefing? must they not have been briefing?