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