could black
Regular verb: black - blacked- blacked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could black
you could black
he could black
we could black
you could black
they could black 	I could be blacking
you could be blacking
he could be blacking
we could be blacking
you could be blacking
they could be blacking	I could have blacked
you could have blacked
he could have blacked
we could have blacked
you could have blacked
they could have blacked	I could have been blacking
you could have been blacking
he could have been blacking
we could have been blacking
you could have been blacking
they could have been blacking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't black
you couldn't black
he couldn't black
we couldn't black
you couldn't black
they couldn't black 	I couldn't be blacking
you couldn't be blacking
he couldn't be blacking
we couldn't be blacking
you couldn't be blacking
they couldn't be blacking	I couldn't have blacked
you couldn't have blacked
he couldn't have blacked
we couldn't have blacked
you couldn't have blacked
they couldn't have blacked	I couldn't have been blacking
you couldn't have been blacking
he couldn't have been blacking
we couldn't have been blacking
you couldn't have been blacking
they couldn't have been blacking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I black?
could you black?
could he black?
could we black?
could you black?
could they black? 	could I be blacking?
could you be blacking?
could he be blacking?
could we be blacking?
could you be blacking?
could they be blacking? 	could I have blacked?
could you have blacked?
could he have blacked?
could we have blacked?
could you have blacked?
could they have blacked? 	could I have been blacking?
could you have been blacking?
could he have been blacking?
could we have been blacking?
could you have been blacking?
could they have been blacking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I black?
couldn't you black?
couldn't he black?
couldn't we black?
couldn't you black?
couldn't they black? 	couldn't I be blacking?
couldn't you be blacking?
couldn't he be blacking?
couldn't we be blacking?
couldn't you be blacking?
couldn't they be blacking? 	couldn't I have blacked?
couldn't you have blacked?
couldn't he have blacked?
couldn't we have blacked?
couldn't you have blacked?
couldn't they have blacked? 	couldn't I have been blacking?
couldn't you have been blacking?
couldn't he have been blacking?
couldn't we have been blacking?
couldn't you have been blacking?
couldn't they have been blacking?