English verb conjugation
MUST GUFFAW

Regular verb: guffaw - guffawed - guffawed

Affirmation

Simple form	V-ing form
I must guffaw you must guffaw he must guffaw we must guffaw you must guffaw they must guffaw	I must be guffawing you must be guffawing he must be guffawing we must be guffawing you must be guffawing they must be guffawing
Perfect	V-ing perfect
I must have guffawed you must have guffawed he must have guffawed we must have guffawed you must have guffawed they must have guffawed	I must have been guffawing you must have been guffawing he must have been guffawing we must have been guffawing you must have been guffawing they must have been guffawing

Negation

Simple form	V-ing form
I mustn't guffaw you mustn't guffaw he mustn't guffaw we mustn't guffaw you mustn't guffaw they mustn't guffaw	I mustn't be guffawing you mustn't be guffawing he mustn't be guffawing we mustn't be guffawing you mustn't be guffawing they mustn't be guffawing
Perfect	V-ing perfect
I mustn't have guffawed you mustn't have guffawed he mustn't have guffawed we mustn't have guffawed you mustn't have guffawed they mustn't have guffawed	I mustn't have been guffawing you mustn't have been guffawing he mustn't have been guffawing we mustn't have been guffawing you mustn't have been guffawing they mustn't have been guffawing

Interrogative form

Simple form	V-ing form
must I guffaw? must you guffaw? must he guffaw? must we guffaw? must you guffaw? must they guffaw?	must I be guffawing? must you be guffawing? must he be guffawing? must we be guffawing? must you be guffawing? must they be guffawing?
Perfect	V-ing perfect
must I have guffawed? must you have guffawed? must he have guffawed? must we have guffawed? must you have guffawed? must they have guffawed?	must I have been guffawing? must you have been guffawing? must he have been guffawing? must we have been guffawing? must you have been guffawing? must they have been guffawing?

Interro-negative form

Simple form	V-ing form
mustn't I guffaw? mustn't you guffaw? mustn't he guffaw? mustn't we guffaw? mustn't you guffaw? mustn't they guffaw?	mustn't I be guffawing? mustn't you be guffawing? mustn't he be guffawing? mustn't we be guffawing? mustn't you be guffawing? mustn't they be guffawing?
Perfect	V-ing perfect
mustn't I have guffawed? mustn't you have guffawed? mustn't he have guffawed? mustn't we have guffawed? mustn't you have guffawed? mustn't they have guffawed?	mustn't I have been guffawing? mustn't you have been guffawing? mustn't he have been guffawing? mustn't we have been guffawing? mustn't you have been guffawing? mustn't they have been guffawing?