could shrill
Verbo regular: shrill - shrilled- shrilled

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could shrill
you could shrill
he could shrill
we could shrill
you could shrill
they could shrill 	I could be shrilling
you could be shrilling
he could be shrilling
we could be shrilling
you could be shrilling
they could be shrilling	I could have shrilled
you could have shrilled
he could have shrilled
we could have shrilled
you could have shrilled
they could have shrilled	I could have been shrilling
you could have been shrilling
he could have been shrilling
we could have been shrilling
you could have been shrilling
they could have been shrilling	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't shrill
you couldn't shrill
he couldn't shrill
we couldn't shrill
you couldn't shrill
they couldn't shrill 	I couldn't be shrilling
you couldn't be shrilling
he couldn't be shrilling
we couldn't be shrilling
you couldn't be shrilling
they couldn't be shrilling	I couldn't have shrilled
you couldn't have shrilled
he couldn't have shrilled
we couldn't have shrilled
you couldn't have shrilled
they couldn't have shrilled	I couldn't have been shrilling
you couldn't have been shrilling
he couldn't have been shrilling
we couldn't have been shrilling
you couldn't have been shrilling
they couldn't have been shrilling	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I shrill?
could you shrill?
could he shrill?
could we shrill?
could you shrill?
could they shrill? 	could I be shrilling?
could you be shrilling?
could he be shrilling?
could we be shrilling?
could you be shrilling?
could they be shrilling? 	could I have shrilled?
could you have shrilled?
could he have shrilled?
could we have shrilled?
could you have shrilled?
could they have shrilled? 	could I have been shrilling?
could you have been shrilling?
could he have been shrilling?
could we have been shrilling?
could you have been shrilling?
could they have been shrilling? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I shrill?
couldn't you shrill?
couldn't he shrill?
couldn't we shrill?
couldn't you shrill?
couldn't they shrill? 	couldn't I be shrilling?
couldn't you be shrilling?
couldn't he be shrilling?
couldn't we be shrilling?
couldn't you be shrilling?
couldn't they be shrilling? 	couldn't I have shrilled?
couldn't you have shrilled?
couldn't he have shrilled?
couldn't we have shrilled?
couldn't you have shrilled?
couldn't they have shrilled? 	couldn't I have been shrilling?
couldn't you have been shrilling?
couldn't he have been shrilling?
couldn't we have been shrilling?
couldn't you have been shrilling?
couldn't they have been shrilling?