could sieve
Verbo regular: sieve - sieved- sieved

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could sieve
you could sieve
he could sieve
we could sieve
you could sieve
they could sieve 	I could be sieving
you could be sieving
he could be sieving
we could be sieving
you could be sieving
they could be sieving	I could have sieved
you could have sieved
he could have sieved
we could have sieved
you could have sieved
they could have sieved	I could have been sieving
you could have been sieving
he could have been sieving
we could have been sieving
you could have been sieving
they could have been sieving	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not sieve
you could not sieve
he could not sieve
we could not sieve
you could not sieve
they could not sieve 	I could not be sieving
you could not be sieving
he could not be sieving
we could not be sieving
you could not be sieving
they could not be sieving	I could not have sieved
you could not have sieved
he could not have sieved
we could not have sieved
you could not have sieved
they could not have sieved	I could not have been sieving
you could not have been sieving
he could not have been sieving
we could not have been sieving
you could not have been sieving
they could not have been sieving	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I sieve?
could you sieve?
could he sieve?
could we sieve?
could you sieve?
could they sieve? 	could I be sieving?
could you be sieving?
could he be sieving?
could we be sieving?
could you be sieving?
could they be sieving? 	could I have sieved?
could you have sieved?
could he have sieved?
could we have sieved?
could you have sieved?
could they have sieved? 	could I have been sieving?
could you have been sieving?
could he have been sieving?
could we have been sieving?
could you have been sieving?
could they have been sieving? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not sieve?
could you not sieve?
could he not sieve?
could we not sieve?
could you not sieve?
could they not sieve? 	could I not be sieving?
could you not be sieving?
could he not be sieving?
could we not be sieving?
could you not be sieving?
could they not be sieving? 	could I not have sieved?
could you not have sieved?
could he not have sieved?
could we not have sieved?
could you not have sieved?
could they not have sieved? 	could I not have been sieving?
could you not have been sieving?
could he not have been sieving?
could we not have been sieving?
could you not have been sieving?
could they not have been sieving?