could exist
Verbo regular: exist - existed- existed

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