English verb conjugation
COULD UNDO

Irregular verb: undo - undid - undone

Affirmation

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

Negation

Simple form	V-ing form
I could not undo you could not undo he could not undo we could not undo you could not undo they could not undo	I could not be undoing you could not be undoing he could not be undoing we could not be undoing you could not be undoing they could not be undoing
Perfect	V-ing perfect
I could not have undone you could not have undone he could not have undone we could not have undone you could not have undone they could not have undone	I could not have been undoing you could not have been undoing he could not have been undoing we could not have been undoing you could not have been undoing they could not have been undoing

Interrogative form

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

Interro-negative form

Simple form	V-ing form
could I not undo? could you not undo? could he not undo? could we not undo? could you not undo? could they not undo?	could I not be undoing? could you not be undoing? could he not be undoing? could we not be undoing? could you not be undoing? could they not be undoing?
Perfect	V-ing perfect
could I not have undone? could you not have undone? could he not have undone? could we not have undone? could you not have undone? could they not have undone?	could I not have been undoing? could you not have been undoing? could he not have been undoing? could we not have been undoing? could you not have been undoing? could they not have been undoing?