I could attend you could attend he could attend we could attend you could attend they could attend
Forma com V-ing
I could be attending you could be attending he could be attending we could be attending you could be attending they could be attending
Perfeito
I could have attended you could have attended he could have attended we could have attended you could have attended they could have attended
Perfeito com V-ing
I could have been attending you could have been attending he could have been attending we could have been attending you could have been attending they could have been attending
Negação
Forma simple
I could not attend you could not attend he could not attend we could not attend you could not attend they could not attend
Forma com V-ing
I could not be attending you could not be attending he could not be attending we could not be attending you could not be attending they could not be attending
Perfeito
I could not have attended you could not have attended he could not have attended we could not have attended you could not have attended they could not have attended
Perfeito com V-ing
I could not have been attending you could not have been attending he could not have been attending we could not have been attending you could not have been attending they could not have been attending
Forma interrogativa
Forma simple
could I attend? could you attend? could he attend? could we attend? could you attend? could they attend?
Forma com V-ing
could I be attending? could you be attending? could he be attending? could we be attending? could you be attending? could they be attending?
Perfeito
could I have attended? could you have attended? could he have attended? could we have attended? could you have attended? could they have attended?
Perfeito com V-ing
could I have been attending? could you have been attending? could he have been attending? could we have been attending? could you have been attending? could they have been attending?
Forma interro-Negação
Forma simple
could I not attend? could you not attend? could he not attend? could we not attend? could you not attend? could they not attend?
Forma com V-ing
could I not be attending? could you not be attending? could he not be attending? could we not be attending? could you not be attending? could they not be attending?
Perfeito
could I not have attended? could you not have attended? could he not have attended? could we not have attended? could you not have attended? could they not have attended?
Perfeito com V-ing
could I not have been attending? could you not have been attending? could he not have been attending? could we not have been attending? could you not have been attending? could they not have been attending?