English verb conjugation
MUST CRUMPLE

Regular verb: crumple - crumpled - crumpled

Affirmation

Simple form	V-ing form
I must crumple you must crumple he must crumple we must crumple you must crumple they must crumple	I must be crumpling you must be crumpling he must be crumpling we must be crumpling you must be crumpling they must be crumpling
Perfect	V-ing perfect
I must have crumpled you must have crumpled he must have crumpled we must have crumpled you must have crumpled they must have crumpled	I must have been crumpling you must have been crumpling he must have been crumpling we must have been crumpling you must have been crumpling they must have been crumpling

Negation

Simple form	V-ing form
I mustn't crumple you mustn't crumple he mustn't crumple we mustn't crumple you mustn't crumple they mustn't crumple	I mustn't be crumpling you mustn't be crumpling he mustn't be crumpling we mustn't be crumpling you mustn't be crumpling they mustn't be crumpling
Perfect	V-ing perfect
I mustn't have crumpled you mustn't have crumpled he mustn't have crumpled we mustn't have crumpled you mustn't have crumpled they mustn't have crumpled	I mustn't have been crumpling you mustn't have been crumpling he mustn't have been crumpling we mustn't have been crumpling you mustn't have been crumpling they mustn't have been crumpling

Interrogative form

Simple form	V-ing form
must I crumple? must you crumple? must he crumple? must we crumple? must you crumple? must they crumple?	must I be crumpling? must you be crumpling? must he be crumpling? must we be crumpling? must you be crumpling? must they be crumpling?
Perfect	V-ing perfect
must I have crumpled? must you have crumpled? must he have crumpled? must we have crumpled? must you have crumpled? must they have crumpled?	must I have been crumpling? must you have been crumpling? must he have been crumpling? must we have been crumpling? must you have been crumpling? must they have been crumpling?

Interro-negative form

Simple form	V-ing form
mustn't I crumple? mustn't you crumple? mustn't he crumple? mustn't we crumple? mustn't you crumple? mustn't they crumple?	mustn't I be crumpling? mustn't you be crumpling? mustn't he be crumpling? mustn't we be crumpling? mustn't you be crumpling? mustn't they be crumpling?
Perfect	V-ing perfect
mustn't I have crumpled? mustn't you have crumpled? mustn't he have crumpled? mustn't we have crumpled? mustn't you have crumpled? mustn't they have crumpled?	mustn't I have been crumpling? mustn't you have been crumpling? mustn't he have been crumpling? mustn't we have been crumpling? mustn't you have been crumpling? mustn't they have been crumpling?