English verb conjugation
COULD LUMBER

Regular verb: lumber - lumbered - lumbered

Affirmation

Simple form	V-ing form
I could lumber you could lumber he could lumber we could lumber you could lumber they could lumber	I could be lumbering you could be lumbering he could be lumbering we could be lumbering you could be lumbering they could be lumbering
Perfect	V-ing perfect
I could have lumbered you could have lumbered he could have lumbered we could have lumbered you could have lumbered they could have lumbered	I could have been lumbering you could have been lumbering he could have been lumbering we could have been lumbering you could have been lumbering they could have been lumbering

Negation

Simple form	V-ing form
I could not lumber you could not lumber he could not lumber we could not lumber you could not lumber they could not lumber	I could not be lumbering you could not be lumbering he could not be lumbering we could not be lumbering you could not be lumbering they could not be lumbering
Perfect	V-ing perfect
I could not have lumbered you could not have lumbered he could not have lumbered we could not have lumbered you could not have lumbered they could not have lumbered	I could not have been lumbering you could not have been lumbering he could not have been lumbering we could not have been lumbering you could not have been lumbering they could not have been lumbering

Interrogative form

Simple form	V-ing form
could I lumber? could you lumber? could he lumber? could we lumber? could you lumber? could they lumber?	could I be lumbering? could you be lumbering? could he be lumbering? could we be lumbering? could you be lumbering? could they be lumbering?
Perfect	V-ing perfect
could I have lumbered? could you have lumbered? could he have lumbered? could we have lumbered? could you have lumbered? could they have lumbered?	could I have been lumbering? could you have been lumbering? could he have been lumbering? could we have been lumbering? could you have been lumbering? could they have been lumbering?

Interro-negative form

Simple form	V-ing form
could I not lumber? could you not lumber? could he not lumber? could we not lumber? could you not lumber? could they not lumber?	could I not be lumbering? could you not be lumbering? could he not be lumbering? could we not be lumbering? could you not be lumbering? could they not be lumbering?
Perfect	V-ing perfect
could I not have lumbered? could you not have lumbered? could he not have lumbered? could we not have lumbered? could you not have lumbered? could they not have lumbered?	could I not have been lumbering? could you not have been lumbering? could he not have been lumbering? could we not have been lumbering? could you not have been lumbering? could they not have been lumbering?