English verb conjugation
MUST UNDO

Irregular verb: undo - undid - undone

Affirmation

Simple form	V-ing form
I must undo you must undo he must undo we must undo you must undo they must undo	I must be undoing you must be undoing he 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 he 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 he 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 he 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 he 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 he 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 he 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 he undo? must we undo? must you undo? must they undo?	must I be undoing? must you be undoing? must he 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 he 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 he 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 he 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 he 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 he 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 he have been undoing? mustn't we have been undoing? mustn't you have been undoing? mustn't they have been undoing?