English verb conjugation
CAN UNDO

Irregular verb: undo - undid - undone

Affirmation

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

Negation

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

Interrogative form

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

Interro-negative form

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