I could write you could write he could write we could write you could write they could write
Forma com V-ing
I could be writing you could be writing he could be writing we could be writing you could be writing they could be writing
Perfeito
I could have written you could have written he could have written we could have written you could have written they could have written
Perfeito com V-ing
I could have been writing you could have been writing he could have been writing we could have been writing you could have been writing they could have been writing
Negação
Forma simple
I could not write you could not write he could not write we could not write you could not write they could not write
Forma com V-ing
I could not be writing you could not be writing he could not be writing we could not be writing you could not be writing they could not be writing
Perfeito
I could not have written you could not have written he could not have written we could not have written you could not have written they could not have written
Perfeito com V-ing
I could not have been writing you could not have been writing he could not have been writing we could not have been writing you could not have been writing they could not have been writing
Forma interrogativa
Forma simple
could I write? could you write? could he write? could we write? could you write? could they write?
Forma com V-ing
could I be writing? could you be writing? could he be writing? could we be writing? could you be writing? could they be writing?
Perfeito
could I have written? could you have written? could he have written? could we have written? could you have written? could they have written?
Perfeito com V-ing
could I have been writing? could you have been writing? could he have been writing? could we have been writing? could you have been writing? could they have been writing?
Forma interro-Negação
Forma simple
could I not write? could you not write? could he not write? could we not write? could you not write? could they not write?
Forma com V-ing
could I not be writing? could you not be writing? could he not be writing? could we not be writing? could you not be writing? could they not be writing?
Perfeito
could I not have written? could you not have written? could he not have written? could we not have written? could you not have written? could they not have written?
Perfeito com V-ing
could I not have been writing? could you not have been writing? could he not have been writing? could we not have been writing? could you not have been writing? could they not have been writing?