I could ring you could ring he could ring we could ring you could ring they could ring
Forma con V-ing
I could be ringing you could be ringing he could be ringing we could be ringing you could be ringing they could be ringing
Perfecto
I could have rung you could have rung he could have rung we could have rung you could have rung they could have rung
Perfecto con V-ing
I could have been ringing you could have been ringing he could have been ringing we could have been ringing you could have been ringing they could have been ringing
Negación
Forma simple
I could not ring you could not ring he could not ring we could not ring you could not ring they could not ring
Forma con V-ing
I could not be ringing you could not be ringing he could not be ringing we could not be ringing you could not be ringing they could not be ringing
Perfecto
I could not have rung you could not have rung he could not have rung we could not have rung you could not have rung they could not have rung
Perfecto con V-ing
I could not have been ringing you could not have been ringing he could not have been ringing we could not have been ringing you could not have been ringing they could not have been ringing
Forma interrogativa
Forma simple
could I ring? could you ring? could he ring? could we ring? could you ring? could they ring?
Forma con V-ing
could I be ringing? could you be ringing? could he be ringing? could we be ringing? could you be ringing? could they be ringing?
Perfecto
could I have rung? could you have rung? could he have rung? could we have rung? could you have rung? could they have rung?
Perfecto con V-ing
could I have been ringing? could you have been ringing? could he have been ringing? could we have been ringing? could you have been ringing? could they have been ringing?
Forma interro-negativa
Forma simple
could I not ring? could you not ring? could he not ring? could we not ring? could you not ring? could they not ring?
Forma con V-ing
could I not be ringing? could you not be ringing? could he not be ringing? could we not be ringing? could you not be ringing? could they not be ringing?
Perfecto
could I not have rung? could you not have rung? could he not have rung? could we not have rung? could you not have rung? could they not have rung?
Perfecto con V-ing
could I not have been ringing? could you not have been ringing? could he not have been ringing? could we not have been ringing? could you not have been ringing? could they not have been ringing?