English verb conjugation
COULD PAPER

Regular verb: paper - papered - papered

Affirmation

Simple form	V-ing form
I could paper you could paper he could paper we could paper you could paper they could paper	I could be papering you could be papering he could be papering we could be papering you could be papering they could be papering
Perfect	V-ing perfect
I could have papered you could have papered he could have papered we could have papered you could have papered they could have papered	I could have been papering you could have been papering he could have been papering we could have been papering you could have been papering they could have been papering

Negation

Simple form	V-ing form
I couldn't paper you couldn't paper he couldn't paper we couldn't paper you couldn't paper they couldn't paper	I couldn't be papering you couldn't be papering he couldn't be papering we couldn't be papering you couldn't be papering they couldn't be papering
Perfect	V-ing perfect
I couldn't have papered you couldn't have papered he couldn't have papered we couldn't have papered you couldn't have papered they couldn't have papered	I couldn't have been papering you couldn't have been papering he couldn't have been papering we couldn't have been papering you couldn't have been papering they couldn't have been papering

Interrogative form

Simple form	V-ing form
could I paper? could you paper? could he paper? could we paper? could you paper? could they paper?	could I be papering? could you be papering? could he be papering? could we be papering? could you be papering? could they be papering?
Perfect	V-ing perfect
could I have papered? could you have papered? could he have papered? could we have papered? could you have papered? could they have papered?	could I have been papering? could you have been papering? could he have been papering? could we have been papering? could you have been papering? could they have been papering?

Interro-negative form

Simple form	V-ing form
couldn't I paper? couldn't you paper? couldn't he paper? couldn't we paper? couldn't you paper? couldn't they paper?	couldn't I be papering? couldn't you be papering? couldn't he be papering? couldn't we be papering? couldn't you be papering? couldn't they be papering?
Perfect	V-ing perfect
couldn't I have papered? couldn't you have papered? couldn't he have papered? couldn't we have papered? couldn't you have papered? couldn't they have papered?	couldn't I have been papering? couldn't you have been papering? couldn't he have been papering? couldn't we have been papering? couldn't you have been papering? couldn't they have been papering?