English verb conjugation
MUST PERK

Regular verb: perk - perked - perked

Affirmation

Simple form	V-ing form
I must perk you must perk he must perk we must perk you must perk they must perk	I must be perking you must be perking he must be perking we must be perking you must be perking they must be perking
Perfect	V-ing perfect
I must have perked you must have perked he must have perked we must have perked you must have perked they must have perked	I must have been perking you must have been perking he must have been perking we must have been perking you must have been perking they must have been perking

Negation

Simple form	V-ing form
I mustn't perk you mustn't perk he mustn't perk we mustn't perk you mustn't perk they mustn't perk	I mustn't be perking you mustn't be perking he mustn't be perking we mustn't be perking you mustn't be perking they mustn't be perking
Perfect	V-ing perfect
I mustn't have perked you mustn't have perked he mustn't have perked we mustn't have perked you mustn't have perked they mustn't have perked	I mustn't have been perking you mustn't have been perking he mustn't have been perking we mustn't have been perking you mustn't have been perking they mustn't have been perking

Interrogative form

Simple form	V-ing form
must I perk? must you perk? must he perk? must we perk? must you perk? must they perk?	must I be perking? must you be perking? must he be perking? must we be perking? must you be perking? must they be perking?
Perfect	V-ing perfect
must I have perked? must you have perked? must he have perked? must we have perked? must you have perked? must they have perked?	must I have been perking? must you have been perking? must he have been perking? must we have been perking? must you have been perking? must they have been perking?

Interro-negative form

Simple form	V-ing form
mustn't I perk? mustn't you perk? mustn't he perk? mustn't we perk? mustn't you perk? mustn't they perk?	mustn't I be perking? mustn't you be perking? mustn't he be perking? mustn't we be perking? mustn't you be perking? mustn't they be perking?
Perfect	V-ing perfect
mustn't I have perked? mustn't you have perked? mustn't he have perked? mustn't we have perked? mustn't you have perked? mustn't they have perked?	mustn't I have been perking? mustn't you have been perking? mustn't he have been perking? mustn't we have been perking? mustn't you have been perking? mustn't they have been perking?