could buff
Regular verb: buff - buffed- buffed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could buff
you could buff
he could buff
we could buff
you could buff
they could buff 	I could be buffing
you could be buffing
he could be buffing
we could be buffing
you could be buffing
they could be buffing	I could have buffed
you could have buffed
he could have buffed
we could have buffed
you could have buffed
they could have buffed	I could have been buffing
you could have been buffing
he could have been buffing
we could have been buffing
you could have been buffing
they could have been buffing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not buff
you could not buff
he could not buff
we could not buff
you could not buff
they could not buff 	I could not be buffing
you could not be buffing
he could not be buffing
we could not be buffing
you could not be buffing
they could not be buffing	I could not have buffed
you could not have buffed
he could not have buffed
we could not have buffed
you could not have buffed
they could not have buffed	I could not have been buffing
you could not have been buffing
he could not have been buffing
we could not have been buffing
you could not have been buffing
they could not have been buffing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I buff?
could you buff?
could he buff?
could we buff?
could you buff?
could they buff? 	could I be buffing?
could you be buffing?
could he be buffing?
could we be buffing?
could you be buffing?
could they be buffing? 	could I have buffed?
could you have buffed?
could he have buffed?
could we have buffed?
could you have buffed?
could they have buffed? 	could I have been buffing?
could you have been buffing?
could he have been buffing?
could we have been buffing?
could you have been buffing?
could they have been buffing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not buff?
could you not buff?
could he not buff?
could we not buff?
could you not buff?
could they not buff? 	could I not be buffing?
could you not be buffing?
could he not be buffing?
could we not be buffing?
could you not be buffing?
could they not be buffing? 	could I not have buffed?
could you not have buffed?
could he not have buffed?
could we not have buffed?
could you not have buffed?
could they not have buffed? 	could I not have been buffing?
could you not have been buffing?
could he not have been buffing?
could we not have been buffing?
could you not have been buffing?
could they not have been buffing?