could prolong
Verbo regular: prolong - prolonged- prolonged

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could prolong
you could prolong
he could prolong
we could prolong
you could prolong
they could prolong 	I could be prolonging
you could be prolonging
he could be prolonging
we could be prolonging
you could be prolonging
they could be prolonging	I could have prolonged
you could have prolonged
he could have prolonged
we could have prolonged
you could have prolonged
they could have prolonged	I could have been prolonging
you could have been prolonging
he could have been prolonging
we could have been prolonging
you could have been prolonging
they could have been prolonging	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not prolong
you could not prolong
he could not prolong
we could not prolong
you could not prolong
they could not prolong 	I could not be prolonging
you could not be prolonging
he could not be prolonging
we could not be prolonging
you could not be prolonging
they could not be prolonging	I could not have prolonged
you could not have prolonged
he could not have prolonged
we could not have prolonged
you could not have prolonged
they could not have prolonged	I could not have been prolonging
you could not have been prolonging
he could not have been prolonging
we could not have been prolonging
you could not have been prolonging
they could not have been prolonging	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I prolong?
could you prolong?
could he prolong?
could we prolong?
could you prolong?
could they prolong? 	could I be prolonging?
could you be prolonging?
could he be prolonging?
could we be prolonging?
could you be prolonging?
could they be prolonging? 	could I have prolonged?
could you have prolonged?
could he have prolonged?
could we have prolonged?
could you have prolonged?
could they have prolonged? 	could I have been prolonging?
could you have been prolonging?
could he have been prolonging?
could we have been prolonging?
could you have been prolonging?
could they have been prolonging? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not prolong?
could you not prolong?
could he not prolong?
could we not prolong?
could you not prolong?
could they not prolong? 	could I not be prolonging?
could you not be prolonging?
could he not be prolonging?
could we not be prolonging?
could you not be prolonging?
could they not be prolonging? 	could I not have prolonged?
could you not have prolonged?
could he not have prolonged?
could we not have prolonged?
could you not have prolonged?
could they not have prolonged? 	could I not have been prolonging?
could you not have been prolonging?
could he not have been prolonging?
could we not have been prolonging?
could you not have been prolonging?
could they not have been prolonging?