English verb conjugation
MUST GRUMP

Regular verb: grump - grumped - grumped

Affirmation

Simple form	V-ing form
I must grump you must grump he must grump we must grump you must grump they must grump	I must be grumping you must be grumping he must be grumping we must be grumping you must be grumping they must be grumping
Perfect	V-ing perfect
I must have grumped you must have grumped he must have grumped we must have grumped you must have grumped they must have grumped	I must have been grumping you must have been grumping he must have been grumping we must have been grumping you must have been grumping they must have been grumping

Negation

Simple form	V-ing form
I mustn't grump you mustn't grump he mustn't grump we mustn't grump you mustn't grump they mustn't grump	I mustn't be grumping you mustn't be grumping he mustn't be grumping we mustn't be grumping you mustn't be grumping they mustn't be grumping
Perfect	V-ing perfect
I mustn't have grumped you mustn't have grumped he mustn't have grumped we mustn't have grumped you mustn't have grumped they mustn't have grumped	I mustn't have been grumping you mustn't have been grumping he mustn't have been grumping we mustn't have been grumping you mustn't have been grumping they mustn't have been grumping

Interrogative form

Simple form	V-ing form
must I grump? must you grump? must he grump? must we grump? must you grump? must they grump?	must I be grumping? must you be grumping? must he be grumping? must we be grumping? must you be grumping? must they be grumping?
Perfect	V-ing perfect
must I have grumped? must you have grumped? must he have grumped? must we have grumped? must you have grumped? must they have grumped?	must I have been grumping? must you have been grumping? must he have been grumping? must we have been grumping? must you have been grumping? must they have been grumping?

Interro-negative form

Simple form	V-ing form
mustn't I grump? mustn't you grump? mustn't he grump? mustn't we grump? mustn't you grump? mustn't they grump?	mustn't I be grumping? mustn't you be grumping? mustn't he be grumping? mustn't we be grumping? mustn't you be grumping? mustn't they be grumping?
Perfect	V-ing perfect
mustn't I have grumped? mustn't you have grumped? mustn't he have grumped? mustn't we have grumped? mustn't you have grumped? mustn't they have grumped?	mustn't I have been grumping? mustn't you have been grumping? mustn't he have been grumping? mustn't we have been grumping? mustn't you have been grumping? mustn't they have been grumping?