English verb conjugation
MUST UNDO

Irregular verb: undo - undid - undone

Affirmation

Simple form	V-ing form
I must undo you must undo she must undo we must undo you must undo they must undo	I must be undoing you must be undoing she must be undoing we must be undoing you must be undoing they must be undoing
Perfect	V-ing perfect
I must have undone you must have undone she must have undone we must have undone you must have undone they must have undone	I must have been undoing you must have been undoing she must have been undoing we must have been undoing you must have been undoing they must have been undoing

Negation

Simple form	V-ing form
I mustn't undo you mustn't undo she mustn't undo we mustn't undo you mustn't undo they mustn't undo	I mustn't be undoing you mustn't be undoing she mustn't be undoing we mustn't be undoing you mustn't be undoing they mustn't be undoing
Perfect	V-ing perfect
I mustn't have undone you mustn't have undone she mustn't have undone we mustn't have undone you mustn't have undone they mustn't have undone	I mustn't have been undoing you mustn't have been undoing she mustn't have been undoing we mustn't have been undoing you mustn't have been undoing they mustn't have been undoing

Interrogative form

Simple form	V-ing form
must I undo? must you undo? must she undo? must we undo? must you undo? must they undo?	must I be undoing? must you be undoing? must she be undoing? must we be undoing? must you be undoing? must they be undoing?
Perfect	V-ing perfect
must I have undone? must you have undone? must she have undone? must we have undone? must you have undone? must they have undone?	must I have been undoing? must you have been undoing? must she have been undoing? must we have been undoing? must you have been undoing? must they have been undoing?

Interro-negative form

Simple form	V-ing form
mustn't I undo? mustn't you undo? mustn't she undo? mustn't we undo? mustn't you undo? mustn't they undo?	mustn't I be undoing? mustn't you be undoing? mustn't she be undoing? mustn't we be undoing? mustn't you be undoing? mustn't they be undoing?
Perfect	V-ing perfect
mustn't I have undone? mustn't you have undone? mustn't she have undone? mustn't we have undone? mustn't you have undone? mustn't they have undone?	mustn't I have been undoing? mustn't you have been undoing? mustn't she have been undoing? mustn't we have been undoing? mustn't you have been undoing? mustn't they have been undoing?