I could listen you could listen he could listen we could listen you could listen they could listen
Forma com V-ing
I could be listening you could be listening he could be listening we could be listening you could be listening they could be listening
Perfeito
I could have listened you could have listened he could have listened we could have listened you could have listened they could have listened
Perfeito com V-ing
I could have been listening you could have been listening he could have been listening we could have been listening you could have been listening they could have been listening
Negação
Forma simple
I could not listen you could not listen he could not listen we could not listen you could not listen they could not listen
Forma com V-ing
I could not be listening you could not be listening he could not be listening we could not be listening you could not be listening they could not be listening
Perfeito
I could not have listened you could not have listened he could not have listened we could not have listened you could not have listened they could not have listened
Perfeito com V-ing
I could not have been listening you could not have been listening he could not have been listening we could not have been listening you could not have been listening they could not have been listening
Forma interrogativa
Forma simple
could I listen? could you listen? could he listen? could we listen? could you listen? could they listen?
Forma com V-ing
could I be listening? could you be listening? could he be listening? could we be listening? could you be listening? could they be listening?
Perfeito
could I have listened? could you have listened? could he have listened? could we have listened? could you have listened? could they have listened?
Perfeito com V-ing
could I have been listening? could you have been listening? could he have been listening? could we have been listening? could you have been listening? could they have been listening?
Forma interro-Negação
Forma simple
could I not listen? could you not listen? could he not listen? could we not listen? could you not listen? could they not listen?
Forma com V-ing
could I not be listening? could you not be listening? could he not be listening? could we not be listening? could you not be listening? could they not be listening?
Perfeito
could I not have listened? could you not have listened? could he not have listened? could we not have listened? could you not have listened? could they not have listened?
Perfeito com V-ing
could I not have been listening? could you not have been listening? could he not have been listening? could we not have been listening? could you not have been listening? could they not have been listening?