could billow
Verbo regular: billow - billowed- billowed

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could billow
you could billow
he could billow
we could billow
you could billow
they could billow 	I could be billowing
you could be billowing
he could be billowing
we could be billowing
you could be billowing
they could be billowing	I could have billowed
you could have billowed
he could have billowed
we could have billowed
you could have billowed
they could have billowed	I could have been billowing
you could have been billowing
he could have been billowing
we could have been billowing
you could have been billowing
they could have been billowing	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not billow
you could not billow
he could not billow
we could not billow
you could not billow
they could not billow 	I could not be billowing
you could not be billowing
he could not be billowing
we could not be billowing
you could not be billowing
they could not be billowing	I could not have billowed
you could not have billowed
he could not have billowed
we could not have billowed
you could not have billowed
they could not have billowed	I could not have been billowing
you could not have been billowing
he could not have been billowing
we could not have been billowing
you could not have been billowing
they could not have been billowing	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I billow?
could you billow?
could he billow?
could we billow?
could you billow?
could they billow? 	could I be billowing?
could you be billowing?
could he be billowing?
could we be billowing?
could you be billowing?
could they be billowing? 	could I have billowed?
could you have billowed?
could he have billowed?
could we have billowed?
could you have billowed?
could they have billowed? 	could I have been billowing?
could you have been billowing?
could he have been billowing?
could we have been billowing?
could you have been billowing?
could they have been billowing? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not billow?
could you not billow?
could he not billow?
could we not billow?
could you not billow?
could they not billow? 	could I not be billowing?
could you not be billowing?
could he not be billowing?
could we not be billowing?
could you not be billowing?
could they not be billowing? 	could I not have billowed?
could you not have billowed?
could he not have billowed?
could we not have billowed?
could you not have billowed?
could they not have billowed? 	could I not have been billowing?
could you not have been billowing?
could he not have been billowing?
could we not have been billowing?
could you not have been billowing?
could they not have been billowing?