could screen
Verbo regular: screen - screened- screened

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could screen
you could screen
he could screen
we could screen
you could screen
they could screen 	I could be screening
you could be screening
he could be screening
we could be screening
you could be screening
they could be screening	I could have screened
you could have screened
he could have screened
we could have screened
you could have screened
they could have screened	I could have been screening
you could have been screening
he could have been screening
we could have been screening
you could have been screening
they could have been screening	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could not screen
you could not screen
he could not screen
we could not screen
you could not screen
they could not screen 	I could not be screening
you could not be screening
he could not be screening
we could not be screening
you could not be screening
they could not be screening	I could not have screened
you could not have screened
he could not have screened
we could not have screened
you could not have screened
they could not have screened	I could not have been screening
you could not have been screening
he could not have been screening
we could not have been screening
you could not have been screening
they could not have been screening	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I screen?
could you screen?
could he screen?
could we screen?
could you screen?
could they screen? 	could I be screening?
could you be screening?
could he be screening?
could we be screening?
could you be screening?
could they be screening? 	could I have screened?
could you have screened?
could he have screened?
could we have screened?
could you have screened?
could they have screened? 	could I have been screening?
could you have been screening?
could he have been screening?
could we have been screening?
could you have been screening?
could they have been screening? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I not screen?
could you not screen?
could he not screen?
could we not screen?
could you not screen?
could they not screen? 	could I not be screening?
could you not be screening?
could he not be screening?
could we not be screening?
could you not be screening?
could they not be screening? 	could I not have screened?
could you not have screened?
could he not have screened?
could we not have screened?
could you not have screened?
could they not have screened? 	could I not have been screening?
could you not have been screening?
could he not have been screening?
could we not have been screening?
could you not have been screening?
could they not have been screening?