could scratch
Verbo regular: scratch - scratched- scratched

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could scratch
you could scratch
he could scratch
we could scratch
you could scratch
they could scratch 	I could be scratching
you could be scratching
he could be scratching
we could be scratching
you could be scratching
they could be scratching	I could have scratched
you could have scratched
he could have scratched
we could have scratched
you could have scratched
they could have scratched	I could have been scratching
you could have been scratching
he could have been scratching
we could have been scratching
you could have been scratching
they could have been scratching	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could not scratch
you could not scratch
he could not scratch
we could not scratch
you could not scratch
they could not scratch 	I could not be scratching
you could not be scratching
he could not be scratching
we could not be scratching
you could not be scratching
they could not be scratching	I could not have scratched
you could not have scratched
he could not have scratched
we could not have scratched
you could not have scratched
they could not have scratched	I could not have been scratching
you could not have been scratching
he could not have been scratching
we could not have been scratching
you could not have been scratching
they could not have been scratching	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I scratch?
could you scratch?
could he scratch?
could we scratch?
could you scratch?
could they scratch? 	could I be scratching?
could you be scratching?
could he be scratching?
could we be scratching?
could you be scratching?
could they be scratching? 	could I have scratched?
could you have scratched?
could he have scratched?
could we have scratched?
could you have scratched?
could they have scratched? 	could I have been scratching?
could you have been scratching?
could he have been scratching?
could we have been scratching?
could you have been scratching?
could they have been scratching? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I not scratch?
could you not scratch?
could he not scratch?
could we not scratch?
could you not scratch?
could they not scratch? 	could I not be scratching?
could you not be scratching?
could he not be scratching?
could we not be scratching?
could you not be scratching?
could they not be scratching? 	could I not have scratched?
could you not have scratched?
could he not have scratched?
could we not have scratched?
could you not have scratched?
could they not have scratched? 	could I not have been scratching?
could you not have been scratching?
could he not have been scratching?
could we not have been scratching?
could you not have been scratching?
could they not have been scratching?