could checker
Regular verb: checker - checkered- checkered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could checker
you could checker
he could checker
we could checker
you could checker
they could checker 	I could be checkering
you could be checkering
he could be checkering
we could be checkering
you could be checkering
they could be checkering	I could have checkered
you could have checkered
he could have checkered
we could have checkered
you could have checkered
they could have checkered	I could have been checkering
you could have been checkering
he could have been checkering
we could have been checkering
you could have been checkering
they could have been checkering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't checker
you couldn't checker
he couldn't checker
we couldn't checker
you couldn't checker
they couldn't checker 	I couldn't be checkering
you couldn't be checkering
he couldn't be checkering
we couldn't be checkering
you couldn't be checkering
they couldn't be checkering	I couldn't have checkered
you couldn't have checkered
he couldn't have checkered
we couldn't have checkered
you couldn't have checkered
they couldn't have checkered	I couldn't have been checkering
you couldn't have been checkering
he couldn't have been checkering
we couldn't have been checkering
you couldn't have been checkering
they couldn't have been checkering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I checker?
could you checker?
could he checker?
could we checker?
could you checker?
could they checker? 	could I be checkering?
could you be checkering?
could he be checkering?
could we be checkering?
could you be checkering?
could they be checkering? 	could I have checkered?
could you have checkered?
could he have checkered?
could we have checkered?
could you have checkered?
could they have checkered? 	could I have been checkering?
could you have been checkering?
could he have been checkering?
could we have been checkering?
could you have been checkering?
could they have been checkering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I checker?
couldn't you checker?
couldn't he checker?
couldn't we checker?
couldn't you checker?
couldn't they checker? 	couldn't I be checkering?
couldn't you be checkering?
couldn't he be checkering?
couldn't we be checkering?
couldn't you be checkering?
couldn't they be checkering? 	couldn't I have checkered?
couldn't you have checkered?
couldn't he have checkered?
couldn't we have checkered?
couldn't you have checkered?
couldn't they have checkered? 	couldn't I have been checkering?
couldn't you have been checkering?
couldn't he have been checkering?
couldn't we have been checkering?
couldn't you have been checkering?
couldn't they have been checkering?