could shutter
Verbo regular: shutter - shuttered- shuttered

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con 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	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I couldn't shutter
you couldn't shutter
he couldn't shutter
we couldn't shutter
you couldn't shutter
they couldn't shutter 	I couldn't be shuttering
you couldn't be shuttering
he couldn't be shuttering
we couldn't be shuttering
you couldn't be shuttering
they couldn't be shuttering	I couldn't have shuttered
you couldn't have shuttered
he couldn't have shuttered
we couldn't have shuttered
you couldn't have shuttered
they couldn't have shuttered	I couldn't have been shuttering
you couldn't have been shuttering
he couldn't have been shuttering
we couldn't have been shuttering
you couldn't have been shuttering
they couldn't have been shuttering	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con 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-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
couldn't I shutter?
couldn't you shutter?
couldn't he shutter?
couldn't we shutter?
couldn't you shutter?
couldn't they shutter? 	couldn't I be shuttering?
couldn't you be shuttering?
couldn't he be shuttering?
couldn't we be shuttering?
couldn't you be shuttering?
couldn't they be shuttering? 	couldn't I have shuttered?
couldn't you have shuttered?
couldn't he have shuttered?
couldn't we have shuttered?
couldn't you have shuttered?
couldn't they have shuttered? 	couldn't I have been shuttering?
couldn't you have been shuttering?
couldn't he have been shuttering?
couldn't we have been shuttering?
couldn't you have been shuttering?
couldn't they have been shuttering?