could snowball
Verbo regular: snowball - snowballed- snowballed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could snowball
you could snowball
she could snowball
we could snowball
you could snowball
they could snowball 	I could be snowballing
you could be snowballing
she could be snowballing
we could be snowballing
you could be snowballing
they could be snowballing	I could have snowballed
you could have snowballed
she could have snowballed
we could have snowballed
you could have snowballed
they could have snowballed	I could have been snowballing
you could have been snowballing
she could have been snowballing
we could have been snowballing
you could have been snowballing
they could have been snowballing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could not snowball
you could not snowball
she could not snowball
we could not snowball
you could not snowball
they could not snowball 	I could not be snowballing
you could not be snowballing
she could not be snowballing
we could not be snowballing
you could not be snowballing
they could not be snowballing	I could not have snowballed
you could not have snowballed
she could not have snowballed
we could not have snowballed
you could not have snowballed
they could not have snowballed	I could not have been snowballing
you could not have been snowballing
she could not have been snowballing
we could not have been snowballing
you could not have been snowballing
they could not have been snowballing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I snowball?
could you snowball?
could she snowball?
could we snowball?
could you snowball?
could they snowball? 	could I be snowballing?
could you be snowballing?
could she be snowballing?
could we be snowballing?
could you be snowballing?
could they be snowballing? 	could I have snowballed?
could you have snowballed?
could she have snowballed?
could we have snowballed?
could you have snowballed?
could they have snowballed? 	could I have been snowballing?
could you have been snowballing?
could she have been snowballing?
could we have been snowballing?
could you have been snowballing?
could they have been snowballing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I not snowball?
could you not snowball?
could she not snowball?
could we not snowball?
could you not snowball?
could they not snowball? 	could I not be snowballing?
could you not be snowballing?
could she not be snowballing?
could we not be snowballing?
could you not be snowballing?
could they not be snowballing? 	could I not have snowballed?
could you not have snowballed?
could she not have snowballed?
could we not have snowballed?
could you not have snowballed?
could they not have snowballed? 	could I not have been snowballing?
could you not have been snowballing?
could she not have been snowballing?
could we not have been snowballing?
could you not have been snowballing?
could they not have been snowballing?