could dun
Verbo regular: dun - dunned- dunned

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could dun
you could dun
he could dun
we could dun
you could dun
they could dun 	I could be dunning
you could be dunning
he could be dunning
we could be dunning
you could be dunning
they could be dunning	I could have dunned
you could have dunned
he could have dunned
we could have dunned
you could have dunned
they could have dunned	I could have been dunning
you could have been dunning
he could have been dunning
we could have been dunning
you could have been dunning
they could have been dunning	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not dun
you could not dun
he could not dun
we could not dun
you could not dun
they could not dun 	I could not be dunning
you could not be dunning
he could not be dunning
we could not be dunning
you could not be dunning
they could not be dunning	I could not have dunned
you could not have dunned
he could not have dunned
we could not have dunned
you could not have dunned
they could not have dunned	I could not have been dunning
you could not have been dunning
he could not have been dunning
we could not have been dunning
you could not have been dunning
they could not have been dunning	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I dun?
could you dun?
could he dun?
could we dun?
could you dun?
could they dun? 	could I be dunning?
could you be dunning?
could he be dunning?
could we be dunning?
could you be dunning?
could they be dunning? 	could I have dunned?
could you have dunned?
could he have dunned?
could we have dunned?
could you have dunned?
could they have dunned? 	could I have been dunning?
could you have been dunning?
could he have been dunning?
could we have been dunning?
could you have been dunning?
could they have been dunning? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not dun?
could you not dun?
could he not dun?
could we not dun?
could you not dun?
could they not dun? 	could I not be dunning?
could you not be dunning?
could he not be dunning?
could we not be dunning?
could you not be dunning?
could they not be dunning? 	could I not have dunned?
could you not have dunned?
could he not have dunned?
could we not have dunned?
could you not have dunned?
could they not have dunned? 	could I not have been dunning?
could you not have been dunning?
could he not have been dunning?
could we not have been dunning?
could you not have been dunning?
could they not have been dunning?