could lumber
Regular verb: lumber - lumbered- lumbered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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	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 	Perfect 	V-ing perfect 	
I couldn't lumber
you couldn't lumber
he couldn't lumber
we couldn't lumber
you couldn't lumber
they couldn't lumber 	I couldn't be lumbering
you couldn't be lumbering
he couldn't be lumbering
we couldn't be lumbering
you couldn't be lumbering
they couldn't be lumbering	I couldn't have lumbered
you couldn't have lumbered
he couldn't have lumbered
we couldn't have lumbered
you couldn't have lumbered
they couldn't have lumbered	I couldn't have been lumbering
you couldn't have been lumbering
he couldn't have been lumbering
we couldn't have been lumbering
you couldn't have been lumbering
they couldn't have been lumbering	

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