English verb conjugation
MUST LUFF

Regular verb: luff - luffed - luffed

Affirmation

Simple form	V-ing form
I must luff you must luff he must luff we must luff you must luff they must luff	I must be luffing you must be luffing he must be luffing we must be luffing you must be luffing they must be luffing
Perfect	V-ing perfect
I must have luffed you must have luffed he must have luffed we must have luffed you must have luffed they must have luffed	I must have been luffing you must have been luffing he must have been luffing we must have been luffing you must have been luffing they must have been luffing

Negation

Simple form	V-ing form
I mustn't luff you mustn't luff he mustn't luff we mustn't luff you mustn't luff they mustn't luff	I mustn't be luffing you mustn't be luffing he mustn't be luffing we mustn't be luffing you mustn't be luffing they mustn't be luffing
Perfect	V-ing perfect
I mustn't have luffed you mustn't have luffed he mustn't have luffed we mustn't have luffed you mustn't have luffed they mustn't have luffed	I mustn't have been luffing you mustn't have been luffing he mustn't have been luffing we mustn't have been luffing you mustn't have been luffing they mustn't have been luffing

Interrogative form

Simple form	V-ing form
must I luff? must you luff? must he luff? must we luff? must you luff? must they luff?	must I be luffing? must you be luffing? must he be luffing? must we be luffing? must you be luffing? must they be luffing?
Perfect	V-ing perfect
must I have luffed? must you have luffed? must he have luffed? must we have luffed? must you have luffed? must they have luffed?	must I have been luffing? must you have been luffing? must he have been luffing? must we have been luffing? must you have been luffing? must they have been luffing?

Interro-negative form

Simple form	V-ing form
mustn't I luff? mustn't you luff? mustn't he luff? mustn't we luff? mustn't you luff? mustn't they luff?	mustn't I be luffing? mustn't you be luffing? mustn't he be luffing? mustn't we be luffing? mustn't you be luffing? mustn't they be luffing?
Perfect	V-ing perfect
mustn't I have luffed? mustn't you have luffed? mustn't he have luffed? mustn't we have luffed? mustn't you have luffed? mustn't they have luffed?	mustn't I have been luffing? mustn't you have been luffing? mustn't he have been luffing? mustn't we have been luffing? mustn't you have been luffing? mustn't they have been luffing?