could background
Verbo regular: background - backgrounded- backgrounded

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could background
you could background
he could background
we could background
you could background
they could background 	I could be backgrounding
you could be backgrounding
he could be backgrounding
we could be backgrounding
you could be backgrounding
they could be backgrounding	I could have backgrounded
you could have backgrounded
he could have backgrounded
we could have backgrounded
you could have backgrounded
they could have backgrounded	I could have been backgrounding
you could have been backgrounding
he could have been backgrounding
we could have been backgrounding
you could have been backgrounding
they could have been backgrounding	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not background
you could not background
he could not background
we could not background
you could not background
they could not background 	I could not be backgrounding
you could not be backgrounding
he could not be backgrounding
we could not be backgrounding
you could not be backgrounding
they could not be backgrounding	I could not have backgrounded
you could not have backgrounded
he could not have backgrounded
we could not have backgrounded
you could not have backgrounded
they could not have backgrounded	I could not have been backgrounding
you could not have been backgrounding
he could not have been backgrounding
we could not have been backgrounding
you could not have been backgrounding
they could not have been backgrounding	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I background?
could you background?
could he background?
could we background?
could you background?
could they background? 	could I be backgrounding?
could you be backgrounding?
could he be backgrounding?
could we be backgrounding?
could you be backgrounding?
could they be backgrounding? 	could I have backgrounded?
could you have backgrounded?
could he have backgrounded?
could we have backgrounded?
could you have backgrounded?
could they have backgrounded? 	could I have been backgrounding?
could you have been backgrounding?
could he have been backgrounding?
could we have been backgrounding?
could you have been backgrounding?
could they have been backgrounding? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not background?
could you not background?
could he not background?
could we not background?
could you not background?
could they not background? 	could I not be backgrounding?
could you not be backgrounding?
could he not be backgrounding?
could we not be backgrounding?
could you not be backgrounding?
could they not be backgrounding? 	could I not have backgrounded?
could you not have backgrounded?
could he not have backgrounded?
could we not have backgrounded?
could you not have backgrounded?
could they not have backgrounded? 	could I not have been backgrounding?
could you not have been backgrounding?
could he not have been backgrounding?
could we not have been backgrounding?
could you not have been backgrounding?
could they not have been backgrounding?