could lumber
Regular verb: lumber - lumbered- lumbered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could lumber
you could lumber
she could lumber
we could lumber
you could lumber
they could lumber 	I could be lumbering
you could be lumbering
she could be lumbering
we could be lumbering
you could be lumbering
they could be lumbering	I could have lumbered
you could have lumbered
she 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
she 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 could not lumber
you could not lumber
she could not lumber
we could not lumber
you could not lumber
they could not lumber 	I could not be lumbering
you could not be lumbering
she could not be lumbering
we could not be lumbering
you could not be lumbering
they could not be lumbering	I could not have lumbered
you could not have lumbered
she could not have lumbered
we could not have lumbered
you could not have lumbered
they could not have lumbered	I could not have been lumbering
you could not have been lumbering
she could not have been lumbering
we could not have been lumbering
you could not have been lumbering
they could not have been lumbering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I lumber?
could you lumber?
could she lumber?
could we lumber?
could you lumber?
could they lumber? 	could I be lumbering?
could you be lumbering?
could she be lumbering?
could we be lumbering?
could you be lumbering?
could they be lumbering? 	could I have lumbered?
could you have lumbered?
could she 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 she 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 	
could I not lumber?
could you not lumber?
could she not lumber?
could we not lumber?
could you not lumber?
could they not lumber? 	could I not be lumbering?
could you not be lumbering?
could she not be lumbering?
could we not be lumbering?
could you not be lumbering?
could they not be lumbering? 	could I not have lumbered?
could you not have lumbered?
could she not have lumbered?
could we not have lumbered?
could you not have lumbered?
could they not have lumbered? 	could I not have been lumbering?
could you not have been lumbering?
could she not have been lumbering?
could we not have been lumbering?
could you not have been lumbering?
could they not have been lumbering?