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 can't lumber you can't lumber he 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 he 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 he 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 he 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 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't I lumber? can't you lumber? can't he 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 he 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 he 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 he have been lumbering? can't we have been lumbering? can't you have been lumbering? can't they have been lumbering?