English verb conjugation
MUST GRIMACE

Regular verb: grimace - grimaced - grimaced

Affirmation

Simple form	V-ing form
I must grimace you must grimace he must grimace we must grimace you must grimace they must grimace	I must be grimacing you must be grimacing he must be grimacing we must be grimacing you must be grimacing they must be grimacing
Perfect	V-ing perfect
I must have grimaced you must have grimaced he must have grimaced we must have grimaced you must have grimaced they must have grimaced	I must have been grimacing you must have been grimacing he must have been grimacing we must have been grimacing you must have been grimacing they must have been grimacing

Negation

Simple form	V-ing form
I mustn't grimace you mustn't grimace he mustn't grimace we mustn't grimace you mustn't grimace they mustn't grimace	I mustn't be grimacing you mustn't be grimacing he mustn't be grimacing we mustn't be grimacing you mustn't be grimacing they mustn't be grimacing
Perfect	V-ing perfect
I mustn't have grimaced you mustn't have grimaced he mustn't have grimaced we mustn't have grimaced you mustn't have grimaced they mustn't have grimaced	I mustn't have been grimacing you mustn't have been grimacing he mustn't have been grimacing we mustn't have been grimacing you mustn't have been grimacing they mustn't have been grimacing

Interrogative form

Simple form	V-ing form
must I grimace? must you grimace? must he grimace? must we grimace? must you grimace? must they grimace?	must I be grimacing? must you be grimacing? must he be grimacing? must we be grimacing? must you be grimacing? must they be grimacing?
Perfect	V-ing perfect
must I have grimaced? must you have grimaced? must he have grimaced? must we have grimaced? must you have grimaced? must they have grimaced?	must I have been grimacing? must you have been grimacing? must he have been grimacing? must we have been grimacing? must you have been grimacing? must they have been grimacing?

Interro-negative form

Simple form	V-ing form
mustn't I grimace? mustn't you grimace? mustn't he grimace? mustn't we grimace? mustn't you grimace? mustn't they grimace?	mustn't I be grimacing? mustn't you be grimacing? mustn't he be grimacing? mustn't we be grimacing? mustn't you be grimacing? mustn't they be grimacing?
Perfect	V-ing perfect
mustn't I have grimaced? mustn't you have grimaced? mustn't he have grimaced? mustn't we have grimaced? mustn't you have grimaced? mustn't they have grimaced?	mustn't I have been grimacing? mustn't you have been grimacing? mustn't he have been grimacing? mustn't we have been grimacing? mustn't you have been grimacing? mustn't they have been grimacing?