English verb conjugation
MUST WHIFF

Regular verb: whiff - whiffed - whiffed

Affirmation

Simple form	V-ing form
I must whiff you must whiff he must whiff we must whiff you must whiff they must whiff	I must be whiffing you must be whiffing he must be whiffing we must be whiffing you must be whiffing they must be whiffing
Perfect	V-ing perfect
I must have whiffed you must have whiffed he must have whiffed we must have whiffed you must have whiffed they must have whiffed	I must have been whiffing you must have been whiffing he must have been whiffing we must have been whiffing you must have been whiffing they must have been whiffing

Negation

Simple form	V-ing form
I must not whiff you must not whiff he must not whiff we must not whiff you must not whiff they must not whiff	I must not be whiffing you must not be whiffing he must not be whiffing we must not be whiffing you must not be whiffing they must not be whiffing
Perfect	V-ing perfect
I must not have whiffed you must not have whiffed he must not have whiffed we must not have whiffed you must not have whiffed they must not have whiffed	I must not have been whiffing you must not have been whiffing he must not have been whiffing we must not have been whiffing you must not have been whiffing they must not have been whiffing

Interrogative form

Simple form	V-ing form
must I whiff? must you whiff? must he whiff? must we whiff? must you whiff? must they whiff?	must I be whiffing? must you be whiffing? must he be whiffing? must we be whiffing? must you be whiffing? must they be whiffing?
Perfect	V-ing perfect
must I have whiffed? must you have whiffed? must he have whiffed? must we have whiffed? must you have whiffed? must they have whiffed?	must I have been whiffing? must you have been whiffing? must he have been whiffing? must we have been whiffing? must you have been whiffing? must they have been whiffing?

Interro-negative form

Simple form	V-ing form
must I not whiff? must you not whiff? must he not whiff? must we not whiff? must you not whiff? must they not whiff?	must I not be whiffing? must you not be whiffing? must he not be whiffing? must we not be whiffing? must you not be whiffing? must they not be whiffing?
Perfect	V-ing perfect
must I not have whiffed? must you not have whiffed? must he not have whiffed? must we not have whiffed? must you not have whiffed? must they not have whiffed?	must I not have been whiffing? must you not have been whiffing? must he not have been whiffing? must we not have been whiffing? must you not have been whiffing? must they not have been whiffing?