could echo
Verbo regular: echo - echoed- echoed

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could echo
you could echo
she could echo
we could echo
you could echo
they could echo 	I could be echoing
you could be echoing
she could be echoing
we could be echoing
you could be echoing
they could be echoing	I could have echoed
you could have echoed
she could have echoed
we could have echoed
you could have echoed
they could have echoed	I could have been echoing
you could have been echoing
she could have been echoing
we could have been echoing
you could have been echoing
they could have been echoing	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't echo
you couldn't echo
she couldn't echo
we couldn't echo
you couldn't echo
they couldn't echo 	I couldn't be echoing
you couldn't be echoing
she couldn't be echoing
we couldn't be echoing
you couldn't be echoing
they couldn't be echoing	I couldn't have echoed
you couldn't have echoed
she couldn't have echoed
we couldn't have echoed
you couldn't have echoed
they couldn't have echoed	I couldn't have been echoing
you couldn't have been echoing
she couldn't have been echoing
we couldn't have been echoing
you couldn't have been echoing
they couldn't have been echoing	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I echo?
could you echo?
could she echo?
could we echo?
could you echo?
could they echo? 	could I be echoing?
could you be echoing?
could she be echoing?
could we be echoing?
could you be echoing?
could they be echoing? 	could I have echoed?
could you have echoed?
could she have echoed?
could we have echoed?
could you have echoed?
could they have echoed? 	could I have been echoing?
could you have been echoing?
could she have been echoing?
could we have been echoing?
could you have been echoing?
could they have been echoing? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I echo?
couldn't you echo?
couldn't she echo?
couldn't we echo?
couldn't you echo?
couldn't they echo? 	couldn't I be echoing?
couldn't you be echoing?
couldn't she be echoing?
couldn't we be echoing?
couldn't you be echoing?
couldn't they be echoing? 	couldn't I have echoed?
couldn't you have echoed?
couldn't she have echoed?
couldn't we have echoed?
couldn't you have echoed?
couldn't they have echoed? 	couldn't I have been echoing?
couldn't you have been echoing?
couldn't she have been echoing?
couldn't we have been echoing?
couldn't you have been echoing?
couldn't they have been echoing?