can lumber
Regular verb: lumber - lumbered- lumbered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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	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 	Perfect 	V-ing perfect 	
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	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 	Perfect 	V-ing perfect 	
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? 	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 	Perfect 	V-ing perfect 	
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? 	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?