English verb conjugation
CAN LUMBER

Regular verb: lumber - lumbered - lumbered

Affirmation

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

Negation

Simple form	V-ing form
I can't lumber you can't lumber she can't lumber we can't lumber you can't lumber they can't lumber	I can't be lumbering you can't be lumbering she can't be lumbering we can't be lumbering you can't be lumbering they can't be lumbering
Perfect	V-ing perfect
I can't have lumbered you can't have lumbered she can't have lumbered we can't have lumbered you can't have lumbered they can't have lumbered	I can't have been lumbering you can't have been lumbering she can't have been lumbering we can't have been lumbering you can't have been lumbering they can't have been lumbering

Interrogative form

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

Interro-negative form

Simple form	V-ing form
can't I lumber? can't you lumber? can't she lumber? can't we lumber? can't you lumber? can't they lumber?	can't I be lumbering? can't you be lumbering? can't she be lumbering? can't we be lumbering? can't you be lumbering? can't they be lumbering?
Perfect	V-ing perfect
can't I have lumbered? can't you have lumbered? can't she have lumbered? can't we have lumbered? can't you have lumbered? can't they have lumbered?	can't I have been lumbering? can't you have been lumbering? can't she have been lumbering? can't we have been lumbering? can't you have been lumbering? can't they have been lumbering?