could refute
Verbo regular: refute - refuted- refuted

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could refute
you could refute
she could refute
we could refute
you could refute
they could refute 	I could be refuting
you could be refuting
she could be refuting
we could be refuting
you could be refuting
they could be refuting	I could have refuted
you could have refuted
she could have refuted
we could have refuted
you could have refuted
they could have refuted	I could have been refuting
you could have been refuting
she could have been refuting
we could have been refuting
you could have been refuting
they could have been refuting	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not refute
you could not refute
she could not refute
we could not refute
you could not refute
they could not refute 	I could not be refuting
you could not be refuting
she could not be refuting
we could not be refuting
you could not be refuting
they could not be refuting	I could not have refuted
you could not have refuted
she could not have refuted
we could not have refuted
you could not have refuted
they could not have refuted	I could not have been refuting
you could not have been refuting
she could not have been refuting
we could not have been refuting
you could not have been refuting
they could not have been refuting	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I refute?
could you refute?
could she refute?
could we refute?
could you refute?
could they refute? 	could I be refuting?
could you be refuting?
could she be refuting?
could we be refuting?
could you be refuting?
could they be refuting? 	could I have refuted?
could you have refuted?
could she have refuted?
could we have refuted?
could you have refuted?
could they have refuted? 	could I have been refuting?
could you have been refuting?
could she have been refuting?
could we have been refuting?
could you have been refuting?
could they have been refuting? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not refute?
could you not refute?
could she not refute?
could we not refute?
could you not refute?
could they not refute? 	could I not be refuting?
could you not be refuting?
could she not be refuting?
could we not be refuting?
could you not be refuting?
could they not be refuting? 	could I not have refuted?
could you not have refuted?
could she not have refuted?
could we not have refuted?
could you not have refuted?
could they not have refuted? 	could I not have been refuting?
could you not have been refuting?
could she not have been refuting?
could we not have been refuting?
could you not have been refuting?
could they not have been refuting?