I could think you could think he could think we could think you could think they could think
Forma con V-ing
I could be thinking you could be thinking he could be thinking we could be thinking you could be thinking they could be thinking
Perfecto
I could have thought you could have thought he could have thought we could have thought you could have thought they could have thought
Perfecto con V-ing
I could have been thinking you could have been thinking he could have been thinking we could have been thinking you could have been thinking they could have been thinking
Negación
Forma simple
I could not think you could not think he could not think we could not think you could not think they could not think
Forma con V-ing
I could not be thinking you could not be thinking he could not be thinking we could not be thinking you could not be thinking they could not be thinking
Perfecto
I could not have thought you could not have thought he could not have thought we could not have thought you could not have thought they could not have thought
Perfecto con V-ing
I could not have been thinking you could not have been thinking he could not have been thinking we could not have been thinking you could not have been thinking they could not have been thinking
Forma interrogativa
Forma simple
could I think? could you think? could he think? could we think? could you think? could they think?
Forma con V-ing
could I be thinking? could you be thinking? could he be thinking? could we be thinking? could you be thinking? could they be thinking?
Perfecto
could I have thought? could you have thought? could he have thought? could we have thought? could you have thought? could they have thought?
Perfecto con V-ing
could I have been thinking? could you have been thinking? could he have been thinking? could we have been thinking? could you have been thinking? could they have been thinking?
Forma interro-negativa
Forma simple
could I not think? could you not think? could he not think? could we not think? could you not think? could they not think?
Forma con V-ing
could I not be thinking? could you not be thinking? could he not be thinking? could we not be thinking? could you not be thinking? could they not be thinking?
Perfecto
could I not have thought? could you not have thought? could he not have thought? could we not have thought? could you not have thought? could they not have thought?
Perfecto con V-ing
could I not have been thinking? could you not have been thinking? could he not have been thinking? could we not have been thinking? could you not have been thinking? could they not have been thinking?