English verb conjugation
MUST UNDERGIRD

Irregular verb: undergird - undergirt, undergirded - undergirt, undergirded

Affirmation

Simple form	V-ing form
I must undergird you must undergird she must undergird we must undergird you must undergird they must undergird	I must be undergirding you must be undergirding she must be undergirding we must be undergirding you must be undergirding they must be undergirding
Perfect	V-ing perfect
I must have undergirt, undergirded you must have undergirt, undergirded she must have undergirt, undergirded we must have undergirt, undergirded you must have undergirt, undergirded they must have undergirt, undergirded	I must have been undergirding you must have been undergirding she must have been undergirding we must have been undergirding you must have been undergirding they must have been undergirding

Negation

Simple form	V-ing form
I mustn't undergird you mustn't undergird she mustn't undergird we mustn't undergird you mustn't undergird they mustn't undergird	I mustn't be undergirding you mustn't be undergirding she mustn't be undergirding we mustn't be undergirding you mustn't be undergirding they mustn't be undergirding
Perfect	V-ing perfect
I mustn't have undergirt, undergirded you mustn't have undergirt, undergirded she mustn't have undergirt, undergirded we mustn't have undergirt, undergirded you mustn't have undergirt, undergirded they mustn't have undergirt, undergirded	I mustn't have been undergirding you mustn't have been undergirding she mustn't have been undergirding we mustn't have been undergirding you mustn't have been undergirding they mustn't have been undergirding

Interrogative form

Simple form	V-ing form
must I undergird? must you undergird? must she undergird? must we undergird? must you undergird? must they undergird?	must I be undergirding? must you be undergirding? must she be undergirding? must we be undergirding? must you be undergirding? must they be undergirding?
Perfect	V-ing perfect
must I have undergirt, undergirded? must you have undergirt, undergirded? must she have undergirt, undergirded? must we have undergirt, undergirded? must you have undergirt, undergirded? must they have undergirt, undergirded?	must I have been undergirding? must you have been undergirding? must she have been undergirding? must we have been undergirding? must you have been undergirding? must they have been undergirding?

Interro-negative form

Simple form	V-ing form
mustn't I undergird? mustn't you undergird? mustn't she undergird? mustn't we undergird? mustn't you undergird? mustn't they undergird?	mustn't I be undergirding? mustn't you be undergirding? mustn't she be undergirding? mustn't we be undergirding? mustn't you be undergirding? mustn't they be undergirding?
Perfect	V-ing perfect
mustn't I have undergirt, undergirded? mustn't you have undergirt, undergirded? mustn't she have undergirt, undergirded? mustn't we have undergirt, undergirded? mustn't you have undergirt, undergirded? mustn't they have undergirt, undergirded?	mustn't I have been undergirding? mustn't you have been undergirding? mustn't she have been undergirding? mustn't we have been undergirding? mustn't you have been undergirding? mustn't they have been undergirding?