English verb conjugation
MUST SHEAF

Regular verb: sheaf - sheafed - sheafed

Affirmation

Simple form	V-ing form
I must sheaf you must sheaf he must sheaf we must sheaf you must sheaf they must sheaf	I must be sheafing you must be sheafing he must be sheafing we must be sheafing you must be sheafing they must be sheafing
Perfect	V-ing perfect
I must have sheafed you must have sheafed he must have sheafed we must have sheafed you must have sheafed they must have sheafed	I must have been sheafing you must have been sheafing he must have been sheafing we must have been sheafing you must have been sheafing they must have been sheafing

Negation

Simple form	V-ing form
I mustn't sheaf you mustn't sheaf he mustn't sheaf we mustn't sheaf you mustn't sheaf they mustn't sheaf	I mustn't be sheafing you mustn't be sheafing he mustn't be sheafing we mustn't be sheafing you mustn't be sheafing they mustn't be sheafing
Perfect	V-ing perfect
I mustn't have sheafed you mustn't have sheafed he mustn't have sheafed we mustn't have sheafed you mustn't have sheafed they mustn't have sheafed	I mustn't have been sheafing you mustn't have been sheafing he mustn't have been sheafing we mustn't have been sheafing you mustn't have been sheafing they mustn't have been sheafing

Interrogative form

Simple form	V-ing form
must I sheaf? must you sheaf? must he sheaf? must we sheaf? must you sheaf? must they sheaf?	must I be sheafing? must you be sheafing? must he be sheafing? must we be sheafing? must you be sheafing? must they be sheafing?
Perfect	V-ing perfect
must I have sheafed? must you have sheafed? must he have sheafed? must we have sheafed? must you have sheafed? must they have sheafed?	must I have been sheafing? must you have been sheafing? must he have been sheafing? must we have been sheafing? must you have been sheafing? must they have been sheafing?

Interro-negative form

Simple form	V-ing form
mustn't I sheaf? mustn't you sheaf? mustn't he sheaf? mustn't we sheaf? mustn't you sheaf? mustn't they sheaf?	mustn't I be sheafing? mustn't you be sheafing? mustn't he be sheafing? mustn't we be sheafing? mustn't you be sheafing? mustn't they be sheafing?
Perfect	V-ing perfect
mustn't I have sheafed? mustn't you have sheafed? mustn't he have sheafed? mustn't we have sheafed? mustn't you have sheafed? mustn't they have sheafed?	mustn't I have been sheafing? mustn't you have been sheafing? mustn't he have been sheafing? mustn't we have been sheafing? mustn't you have been sheafing? mustn't they have been sheafing?