I could mast you could mast he could mast we could mast you could mast they could mast
Forma con V-ing
I could be masting you could be masting he could be masting we could be masting you could be masting they could be masting
Perfecto
I could have masted you could have masted he could have masted we could have masted you could have masted they could have masted
Perfecto con V-ing
I could have been masting you could have been masting he could have been masting we could have been masting you could have been masting they could have been masting
Negación
Forma simple
I could not mast you could not mast he could not mast we could not mast you could not mast they could not mast
Forma con V-ing
I could not be masting you could not be masting he could not be masting we could not be masting you could not be masting they could not be masting
Perfecto
I could not have masted you could not have masted he could not have masted we could not have masted you could not have masted they could not have masted
Perfecto con V-ing
I could not have been masting you could not have been masting he could not have been masting we could not have been masting you could not have been masting they could not have been masting
Forma interrogativa
Forma simple
could I mast? could you mast? could he mast? could we mast? could you mast? could they mast?
Forma con V-ing
could I be masting? could you be masting? could he be masting? could we be masting? could you be masting? could they be masting?
Perfecto
could I have masted? could you have masted? could he have masted? could we have masted? could you have masted? could they have masted?
Perfecto con V-ing
could I have been masting? could you have been masting? could he have been masting? could we have been masting? could you have been masting? could they have been masting?
Forma interro-negativa
Forma simple
could I not mast? could you not mast? could he not mast? could we not mast? could you not mast? could they not mast?
Forma con V-ing
could I not be masting? could you not be masting? could he not be masting? could we not be masting? could you not be masting? could they not be masting?
Perfecto
could I not have masted? could you not have masted? could he not have masted? could we not have masted? could you not have masted? could they not have masted?
Perfecto con V-ing
could I not have been masting? could you not have been masting? could he not have been masting? could we not have been masting? could you not have been masting? could they not have been masting?