could mast
Verbo regular: mast - masted- masted

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could mast
you could mast
he could mast
we could mast
you could mast
they could mast 	I could be masting
you could be masting
he could be masting
we could be masting
you could be masting
they could be masting	I could have masted
you could have masted
he could have masted
we could have masted
you could have masted
they could have masted	I could have been masting
you could have been masting
he could have been masting
we could have been masting
you could have been masting
they could have been masting	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not mast
you could not mast
he could not mast
we could not mast
you could not mast
they could not mast 	I could not be masting
you could not be masting
he could not be masting
we could not be masting
you could not be masting
they could not be masting	I could not have masted
you could not have masted
he could not have masted
we could not have masted
you could not have masted
they could not have masted	I could not have been masting
you could not have been masting
he could not have been masting
we could not have been masting
you could not have been masting
they could not have been masting	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I mast?
could you mast?
could he mast?
could we mast?
could you mast?
could they mast? 	could I be masting?
could you be masting?
could he be masting?
could we be masting?
could you be masting?
could they be masting? 	could I have masted?
could you have masted?
could he have masted?
could we have masted?
could you have masted?
could they have masted? 	could I have been masting?
could you have been masting?
could he have been masting?
could we have been masting?
could you have been masting?
could they have been masting? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not mast?
could you not mast?
could he not mast?
could we not mast?
could you not mast?
could they not mast? 	could I not be masting?
could you not be masting?
could he not be masting?
could we not be masting?
could you not be masting?
could they not be masting? 	could I not have masted?
could you not have masted?
could he not have masted?
could we not have masted?
could you not have masted?
could they not have masted? 	could I not have been masting?
could you not have been masting?
could he not have been masting?
could we not have been masting?
could you not have been masting?
could they not have been masting?