English verb conjugation
MUST PIPE

Regular verb: pipe - piped - piped

Affirmation

Simple form	V-ing form
I must pipe you must pipe he must pipe we must pipe you must pipe they must pipe	I must be piping you must be piping he must be piping we must be piping you must be piping they must be piping
Perfect	V-ing perfect
I must have piped you must have piped he must have piped we must have piped you must have piped they must have piped	I must have been piping you must have been piping he must have been piping we must have been piping you must have been piping they must have been piping

Negation

Simple form	V-ing form
I mustn't pipe you mustn't pipe he mustn't pipe we mustn't pipe you mustn't pipe they mustn't pipe	I mustn't be piping you mustn't be piping he mustn't be piping we mustn't be piping you mustn't be piping they mustn't be piping
Perfect	V-ing perfect
I mustn't have piped you mustn't have piped he mustn't have piped we mustn't have piped you mustn't have piped they mustn't have piped	I mustn't have been piping you mustn't have been piping he mustn't have been piping we mustn't have been piping you mustn't have been piping they mustn't have been piping

Interrogative form

Simple form	V-ing form
must I pipe? must you pipe? must he pipe? must we pipe? must you pipe? must they pipe?	must I be piping? must you be piping? must he be piping? must we be piping? must you be piping? must they be piping?
Perfect	V-ing perfect
must I have piped? must you have piped? must he have piped? must we have piped? must you have piped? must they have piped?	must I have been piping? must you have been piping? must he have been piping? must we have been piping? must you have been piping? must they have been piping?

Interro-negative form

Simple form	V-ing form
mustn't I pipe? mustn't you pipe? mustn't he pipe? mustn't we pipe? mustn't you pipe? mustn't they pipe?	mustn't I be piping? mustn't you be piping? mustn't he be piping? mustn't we be piping? mustn't you be piping? mustn't they be piping?
Perfect	V-ing perfect
mustn't I have piped? mustn't you have piped? mustn't he have piped? mustn't we have piped? mustn't you have piped? mustn't they have piped?	mustn't I have been piping? mustn't you have been piping? mustn't he have been piping? mustn't we have been piping? mustn't you have been piping? mustn't they have been piping?