could rebut
Regular verb: rebut - rebuted- rebuted

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could rebut
you could rebut
he could rebut
we could rebut
you could rebut
they could rebut 	I could be rebuting
you could be rebuting
he could be rebuting
we could be rebuting
you could be rebuting
they could be rebuting	I could have rebuted
you could have rebuted
he could have rebuted
we could have rebuted
you could have rebuted
they could have rebuted	I could have been rebuting
you could have been rebuting
he could have been rebuting
we could have been rebuting
you could have been rebuting
they could have been rebuting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't rebut
you couldn't rebut
he couldn't rebut
we couldn't rebut
you couldn't rebut
they couldn't rebut 	I couldn't be rebuting
you couldn't be rebuting
he couldn't be rebuting
we couldn't be rebuting
you couldn't be rebuting
they couldn't be rebuting	I couldn't have rebuted
you couldn't have rebuted
he couldn't have rebuted
we couldn't have rebuted
you couldn't have rebuted
they couldn't have rebuted	I couldn't have been rebuting
you couldn't have been rebuting
he couldn't have been rebuting
we couldn't have been rebuting
you couldn't have been rebuting
they couldn't have been rebuting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I rebut?
could you rebut?
could he rebut?
could we rebut?
could you rebut?
could they rebut? 	could I be rebuting?
could you be rebuting?
could he be rebuting?
could we be rebuting?
could you be rebuting?
could they be rebuting? 	could I have rebuted?
could you have rebuted?
could he have rebuted?
could we have rebuted?
could you have rebuted?
could they have rebuted? 	could I have been rebuting?
could you have been rebuting?
could he have been rebuting?
could we have been rebuting?
could you have been rebuting?
could they have been rebuting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I rebut?
couldn't you rebut?
couldn't he rebut?
couldn't we rebut?
couldn't you rebut?
couldn't they rebut? 	couldn't I be rebuting?
couldn't you be rebuting?
couldn't he be rebuting?
couldn't we be rebuting?
couldn't you be rebuting?
couldn't they be rebuting? 	couldn't I have rebuted?
couldn't you have rebuted?
couldn't he have rebuted?
couldn't we have rebuted?
couldn't you have rebuted?
couldn't they have rebuted? 	couldn't I have been rebuting?
couldn't you have been rebuting?
couldn't he have been rebuting?
couldn't we have been rebuting?
couldn't you have been rebuting?
couldn't they have been rebuting?