English verb conjugation
MUST BURP

Regular verb: burp - burped - burped

Affirmation

Simple form	V-ing form
I must burp you must burp he must burp we must burp you must burp they must burp	I must be burping you must be burping he must be burping we must be burping you must be burping they must be burping
Perfect	V-ing perfect
I must have burped you must have burped he must have burped we must have burped you must have burped they must have burped	I must have been burping you must have been burping he must have been burping we must have been burping you must have been burping they must have been burping

Negation

Simple form	V-ing form
I mustn't burp you mustn't burp he mustn't burp we mustn't burp you mustn't burp they mustn't burp	I mustn't be burping you mustn't be burping he mustn't be burping we mustn't be burping you mustn't be burping they mustn't be burping
Perfect	V-ing perfect
I mustn't have burped you mustn't have burped he mustn't have burped we mustn't have burped you mustn't have burped they mustn't have burped	I mustn't have been burping you mustn't have been burping he mustn't have been burping we mustn't have been burping you mustn't have been burping they mustn't have been burping

Interrogative form

Simple form	V-ing form
must I burp? must you burp? must he burp? must we burp? must you burp? must they burp?	must I be burping? must you be burping? must he be burping? must we be burping? must you be burping? must they be burping?
Perfect	V-ing perfect
must I have burped? must you have burped? must he have burped? must we have burped? must you have burped? must they have burped?	must I have been burping? must you have been burping? must he have been burping? must we have been burping? must you have been burping? must they have been burping?

Interro-negative form

Simple form	V-ing form
mustn't I burp? mustn't you burp? mustn't he burp? mustn't we burp? mustn't you burp? mustn't they burp?	mustn't I be burping? mustn't you be burping? mustn't he be burping? mustn't we be burping? mustn't you be burping? mustn't they be burping?
Perfect	V-ing perfect
mustn't I have burped? mustn't you have burped? mustn't he have burped? mustn't we have burped? mustn't you have burped? mustn't they have burped?	mustn't I have been burping? mustn't you have been burping? mustn't he have been burping? mustn't we have been burping? mustn't you have been burping? mustn't they have been burping?