English verb conjugation
MUST PREEN

Regular verb: preen - preened - preened

Affirmation

Simple form	V-ing form
I must preen you must preen he must preen we must preen you must preen they must preen	I must be preening you must be preening he must be preening we must be preening you must be preening they must be preening
Perfect	V-ing perfect
I must have preened you must have preened he must have preened we must have preened you must have preened they must have preened	I must have been preening you must have been preening he must have been preening we must have been preening you must have been preening they must have been preening

Negation

Simple form	V-ing form
I mustn't preen you mustn't preen he mustn't preen we mustn't preen you mustn't preen they mustn't preen	I mustn't be preening you mustn't be preening he mustn't be preening we mustn't be preening you mustn't be preening they mustn't be preening
Perfect	V-ing perfect
I mustn't have preened you mustn't have preened he mustn't have preened we mustn't have preened you mustn't have preened they mustn't have preened	I mustn't have been preening you mustn't have been preening he mustn't have been preening we mustn't have been preening you mustn't have been preening they mustn't have been preening

Interrogative form

Simple form	V-ing form
must I preen? must you preen? must he preen? must we preen? must you preen? must they preen?	must I be preening? must you be preening? must he be preening? must we be preening? must you be preening? must they be preening?
Perfect	V-ing perfect
must I have preened? must you have preened? must he have preened? must we have preened? must you have preened? must they have preened?	must I have been preening? must you have been preening? must he have been preening? must we have been preening? must you have been preening? must they have been preening?

Interro-negative form

Simple form	V-ing form
mustn't I preen? mustn't you preen? mustn't he preen? mustn't we preen? mustn't you preen? mustn't they preen?	mustn't I be preening? mustn't you be preening? mustn't he be preening? mustn't we be preening? mustn't you be preening? mustn't they be preening?
Perfect	V-ing perfect
mustn't I have preened? mustn't you have preened? mustn't he have preened? mustn't we have preened? mustn't you have preened? mustn't they have preened?	mustn't I have been preening? mustn't you have been preening? mustn't he have been preening? mustn't we have been preening? mustn't you have been preening? mustn't they have been preening?