English verb conjugation
CAN LUMBER

Regular verb: lumber - lumbered - lumbered

Affirmation

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

Interrogative form

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