can undo
Irregular verb: undo - undid- undone

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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	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 	Perfect 	V-ing perfect 	
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	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 	Perfect 	V-ing perfect 	
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? 	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 	Perfect 	V-ing perfect 	
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? 	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?