could sledgehammer
Regular verb: sledgehammer - sledgehammered- sledgehammered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could sledgehammer
you could sledgehammer
he could sledgehammer
we could sledgehammer
you could sledgehammer
they could sledgehammer 	I could be sledgehammering
you could be sledgehammering
he could be sledgehammering
we could be sledgehammering
you could be sledgehammering
they could be sledgehammering	I could have sledgehammered
you could have sledgehammered
he could have sledgehammered
we could have sledgehammered
you could have sledgehammered
they could have sledgehammered	I could have been sledgehammering
you could have been sledgehammering
he could have been sledgehammering
we could have been sledgehammering
you could have been sledgehammering
they could have been sledgehammering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't sledgehammer
you couldn't sledgehammer
he couldn't sledgehammer
we couldn't sledgehammer
you couldn't sledgehammer
they couldn't sledgehammer 	I couldn't be sledgehammering
you couldn't be sledgehammering
he couldn't be sledgehammering
we couldn't be sledgehammering
you couldn't be sledgehammering
they couldn't be sledgehammering	I couldn't have sledgehammered
you couldn't have sledgehammered
he couldn't have sledgehammered
we couldn't have sledgehammered
you couldn't have sledgehammered
they couldn't have sledgehammered	I couldn't have been sledgehammering
you couldn't have been sledgehammering
he couldn't have been sledgehammering
we couldn't have been sledgehammering
you couldn't have been sledgehammering
they couldn't have been sledgehammering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I sledgehammer?
could you sledgehammer?
could he sledgehammer?
could we sledgehammer?
could you sledgehammer?
could they sledgehammer? 	could I be sledgehammering?
could you be sledgehammering?
could he be sledgehammering?
could we be sledgehammering?
could you be sledgehammering?
could they be sledgehammering? 	could I have sledgehammered?
could you have sledgehammered?
could he have sledgehammered?
could we have sledgehammered?
could you have sledgehammered?
could they have sledgehammered? 	could I have been sledgehammering?
could you have been sledgehammering?
could he have been sledgehammering?
could we have been sledgehammering?
could you have been sledgehammering?
could they have been sledgehammering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I sledgehammer?
couldn't you sledgehammer?
couldn't he sledgehammer?
couldn't we sledgehammer?
couldn't you sledgehammer?
couldn't they sledgehammer? 	couldn't I be sledgehammering?
couldn't you be sledgehammering?
couldn't he be sledgehammering?
couldn't we be sledgehammering?
couldn't you be sledgehammering?
couldn't they be sledgehammering? 	couldn't I have sledgehammered?
couldn't you have sledgehammered?
couldn't he have sledgehammered?
couldn't we have sledgehammered?
couldn't you have sledgehammered?
couldn't they have sledgehammered? 	couldn't I have been sledgehammering?
couldn't you have been sledgehammering?
couldn't he have been sledgehammering?
couldn't we have been sledgehammering?
couldn't you have been sledgehammering?
couldn't they have been sledgehammering?