must quaff
Regular verb: quaff - quaffed- quaffed

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