Conjugação do verbo inglês
COULD EXIST

Verbo regular: exist - existed - existed

Afirmação

Forma simple	Forma com V-ing
I could exist you could exist he could exist we could exist you could exist they could exist	I could be existing you could be existing he could be existing we could be existing you could be existing they could be existing
Perfeito	Perfeito com V-ing
I could have existed you could have existed he could have existed we could have existed you could have existed they could have existed	I could have been existing you could have been existing he could have been existing we could have been existing you could have been existing they could have been existing

Negação

Forma simple	Forma com V-ing
I could not exist you could not exist he could not exist we could not exist you could not exist they could not exist	I could not be existing you could not be existing he could not be existing we could not be existing you could not be existing they could not be existing
Perfeito	Perfeito com V-ing
I could not have existed you could not have existed he could not have existed we could not have existed you could not have existed they could not have existed	I could not have been existing you could not have been existing he could not have been existing we could not have been existing you could not have been existing they could not have been existing

Forma interrogativa

Forma simple	Forma com V-ing
could I exist? could you exist? could he exist? could we exist? could you exist? could they exist?	could I be existing? could you be existing? could he be existing? could we be existing? could you be existing? could they be existing?
Perfeito	Perfeito com V-ing
could I have existed? could you have existed? could he have existed? could we have existed? could you have existed? could they have existed?	could I have been existing? could you have been existing? could he have been existing? could we have been existing? could you have been existing? could they have been existing?

Forma interro-Negação

Forma simple	Forma com V-ing
could I not exist? could you not exist? could he not exist? could we not exist? could you not exist? could they not exist?	could I not be existing? could you not be existing? could he not be existing? could we not be existing? could you not be existing? could they not be existing?
Perfeito	Perfeito com V-ing
could I not have existed? could you not have existed? could he not have existed? could we not have existed? could you not have existed? could they not have existed?	could I not have been existing? could you not have been existing? could he not have been existing? could we not have been existing? could you not have been existing? could they not have been existing?