English verb conjugation
MUST DARKEN

Regular verb: darken - darkened - darkened

Affirmation

Simple form	V-ing form
I must darken you must darken he must darken we must darken you must darken they must darken	I must be darkening you must be darkening he must be darkening we must be darkening you must be darkening they must be darkening
Perfect	V-ing perfect
I must have darkened you must have darkened he must have darkened we must have darkened you must have darkened they must have darkened	I must have been darkening you must have been darkening he must have been darkening we must have been darkening you must have been darkening they must have been darkening

Negation

Simple form	V-ing form
I mustn't darken you mustn't darken he mustn't darken we mustn't darken you mustn't darken they mustn't darken	I mustn't be darkening you mustn't be darkening he mustn't be darkening we mustn't be darkening you mustn't be darkening they mustn't be darkening
Perfect	V-ing perfect
I mustn't have darkened you mustn't have darkened he mustn't have darkened we mustn't have darkened you mustn't have darkened they mustn't have darkened	I mustn't have been darkening you mustn't have been darkening he mustn't have been darkening we mustn't have been darkening you mustn't have been darkening they mustn't have been darkening

Interrogative form

Simple form	V-ing form
must I darken? must you darken? must he darken? must we darken? must you darken? must they darken?	must I be darkening? must you be darkening? must he be darkening? must we be darkening? must you be darkening? must they be darkening?
Perfect	V-ing perfect
must I have darkened? must you have darkened? must he have darkened? must we have darkened? must you have darkened? must they have darkened?	must I have been darkening? must you have been darkening? must he have been darkening? must we have been darkening? must you have been darkening? must they have been darkening?

Interro-negative form

Simple form	V-ing form
mustn't I darken? mustn't you darken? mustn't he darken? mustn't we darken? mustn't you darken? mustn't they darken?	mustn't I be darkening? mustn't you be darkening? mustn't he be darkening? mustn't we be darkening? mustn't you be darkening? mustn't they be darkening?
Perfect	V-ing perfect
mustn't I have darkened? mustn't you have darkened? mustn't he have darkened? mustn't we have darkened? mustn't you have darkened? mustn't they have darkened?	mustn't I have been darkening? mustn't you have been darkening? mustn't he have been darkening? mustn't we have been darkening? mustn't you have been darkening? mustn't they have been darkening?