could discolor
Regular verb: discolor - discolored- discolored

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could discolor
you could discolor
she could discolor
we could discolor
you could discolor
they could discolor 	I could be discoloring
you could be discoloring
she could be discoloring
we could be discoloring
you could be discoloring
they could be discoloring	I could have discolored
you could have discolored
she could have discolored
we could have discolored
you could have discolored
they could have discolored	I could have been discoloring
you could have been discoloring
she could have been discoloring
we could have been discoloring
you could have been discoloring
they could have been discoloring	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not discolor
you could not discolor
she could not discolor
we could not discolor
you could not discolor
they could not discolor 	I could not be discoloring
you could not be discoloring
she could not be discoloring
we could not be discoloring
you could not be discoloring
they could not be discoloring	I could not have discolored
you could not have discolored
she could not have discolored
we could not have discolored
you could not have discolored
they could not have discolored	I could not have been discoloring
you could not have been discoloring
she could not have been discoloring
we could not have been discoloring
you could not have been discoloring
they could not have been discoloring	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I discolor?
could you discolor?
could she discolor?
could we discolor?
could you discolor?
could they discolor? 	could I be discoloring?
could you be discoloring?
could she be discoloring?
could we be discoloring?
could you be discoloring?
could they be discoloring? 	could I have discolored?
could you have discolored?
could she have discolored?
could we have discolored?
could you have discolored?
could they have discolored? 	could I have been discoloring?
could you have been discoloring?
could she have been discoloring?
could we have been discoloring?
could you have been discoloring?
could they have been discoloring? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not discolor?
could you not discolor?
could she not discolor?
could we not discolor?
could you not discolor?
could they not discolor? 	could I not be discoloring?
could you not be discoloring?
could she not be discoloring?
could we not be discoloring?
could you not be discoloring?
could they not be discoloring? 	could I not have discolored?
could you not have discolored?
could she not have discolored?
could we not have discolored?
could you not have discolored?
could they not have discolored? 	could I not have been discoloring?
could you not have been discoloring?
could she not have been discoloring?
could we not have been discoloring?
could you not have been discoloring?
could they not have been discoloring?