English verb conjugation
MUST QUAFF

Regular verb: quaff - quaffed - quaffed

Affirmation

Simple form	V-ing form
I must quaff you must quaff he must quaff we must quaff you must quaff they must quaff	I must be quaffing you must be quaffing he must be quaffing we must be quaffing you must be quaffing they must be quaffing
Perfect	V-ing perfect
I must have quaffed you must have quaffed he must have quaffed we must have quaffed you must have quaffed they must have quaffed	I must have been quaffing you must have been quaffing he must have been quaffing we must have been quaffing you must have been quaffing they must have been quaffing

Negation

Simple form	V-ing form
I mustn't quaff you mustn't quaff he mustn't quaff we mustn't quaff you mustn't quaff they mustn't quaff	I mustn't be quaffing you mustn't be quaffing he mustn't be quaffing we mustn't be quaffing you mustn't be quaffing they mustn't be quaffing
Perfect	V-ing perfect
I mustn't have quaffed you mustn't have quaffed he mustn't have quaffed we mustn't have quaffed you mustn't have quaffed they mustn't have quaffed	I mustn't have been quaffing you mustn't have been quaffing he mustn't have been quaffing we mustn't have been quaffing you mustn't have been quaffing they mustn't have been quaffing

Interrogative form

Simple form	V-ing form
must I quaff? must you quaff? must he quaff? must we quaff? must you quaff? must they quaff?	must I be quaffing? must you be quaffing? must he be quaffing? must we be quaffing? must you be quaffing? must they be quaffing?
Perfect	V-ing perfect
must I have quaffed? must you have quaffed? must he have quaffed? must we have quaffed? must you have quaffed? must they have quaffed?	must I have been quaffing? must you have been quaffing? must he have been quaffing? must we have been quaffing? must you have been quaffing? must they have been quaffing?

Interro-negative form

Simple form	V-ing form
mustn't I quaff? mustn't you quaff? mustn't he quaff? mustn't we quaff? mustn't you quaff? mustn't they quaff?	mustn't I be quaffing? mustn't you be quaffing? mustn't he be quaffing? mustn't we be quaffing? mustn't you be quaffing? mustn't they be quaffing?
Perfect	V-ing perfect
mustn't I have quaffed? mustn't you have quaffed? mustn't he have quaffed? mustn't we have quaffed? mustn't you have quaffed? mustn't they have quaffed?	mustn't I have been quaffing? mustn't you have been quaffing? mustn't he have been quaffing? mustn't we have been quaffing? mustn't you have been quaffing? mustn't they have been quaffing?