could shutter
Verbo regular: shutter - shuttered- shuttered

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could shutter
you could shutter
he could shutter
we could shutter
you could shutter
they could shutter 	I could be shuttering
you could be shuttering
he could be shuttering
we could be shuttering
you could be shuttering
they could be shuttering	I could have shuttered
you could have shuttered
he could have shuttered
we could have shuttered
you could have shuttered
they could have shuttered	I could have been shuttering
you could have been shuttering
he could have been shuttering
we could have been shuttering
you could have been shuttering
they could have been shuttering	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not shutter
you could not shutter
he could not shutter
we could not shutter
you could not shutter
they could not shutter 	I could not be shuttering
you could not be shuttering
he could not be shuttering
we could not be shuttering
you could not be shuttering
they could not be shuttering	I could not have shuttered
you could not have shuttered
he could not have shuttered
we could not have shuttered
you could not have shuttered
they could not have shuttered	I could not have been shuttering
you could not have been shuttering
he could not have been shuttering
we could not have been shuttering
you could not have been shuttering
they could not have been shuttering	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I shutter?
could you shutter?
could he shutter?
could we shutter?
could you shutter?
could they shutter? 	could I be shuttering?
could you be shuttering?
could he be shuttering?
could we be shuttering?
could you be shuttering?
could they be shuttering? 	could I have shuttered?
could you have shuttered?
could he have shuttered?
could we have shuttered?
could you have shuttered?
could they have shuttered? 	could I have been shuttering?
could you have been shuttering?
could he have been shuttering?
could we have been shuttering?
could you have been shuttering?
could they have been shuttering? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not shutter?
could you not shutter?
could he not shutter?
could we not shutter?
could you not shutter?
could they not shutter? 	could I not be shuttering?
could you not be shuttering?
could he not be shuttering?
could we not be shuttering?
could you not be shuttering?
could they not be shuttering? 	could I not have shuttered?
could you not have shuttered?
could he not have shuttered?
could we not have shuttered?
could you not have shuttered?
could they not have shuttered? 	could I not have been shuttering?
could you not have been shuttering?
could he not have been shuttering?
could we not have been shuttering?
could you not have been shuttering?
could they not have been shuttering?