English verb conjugation
MUST BRIEF

Regular verb: brief - briefed - briefed

Affirmation

Simple form	V-ing form
I must brief you must brief he must brief we must brief you must brief they must brief	I must be briefing you must be briefing he 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 he 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 he 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 mustn't brief you mustn't brief he mustn't brief we mustn't brief you mustn't brief they mustn't brief	I mustn't be briefing you mustn't be briefing he mustn't be briefing we mustn't be briefing you mustn't be briefing they mustn't be briefing
Perfect	V-ing perfect
I mustn't have briefed you mustn't have briefed he mustn't have briefed we mustn't have briefed you mustn't have briefed they mustn't have briefed	I mustn't have been briefing you mustn't have been briefing he mustn't have been briefing we mustn't have been briefing you mustn't have been briefing they mustn't have been briefing

Interrogative form

Simple form	V-ing form
must I brief? must you brief? must he brief? must we brief? must you brief? must they brief?	must I be briefing? must you be briefing? must he 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 he 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 he 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
mustn't I brief? mustn't you brief? mustn't he brief? mustn't we brief? mustn't you brief? mustn't they brief?	mustn't I be briefing? mustn't you be briefing? mustn't he be briefing? mustn't we be briefing? mustn't you be briefing? mustn't they be briefing?
Perfect	V-ing perfect
mustn't I have briefed? mustn't you have briefed? mustn't he have briefed? mustn't we have briefed? mustn't you have briefed? mustn't they have briefed?	mustn't I have been briefing? mustn't you have been briefing? mustn't he have been briefing? mustn't we have been briefing? mustn't you have been briefing? mustn't they have been briefing?