could screen
Regular verb: screen - screened- screened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't screen
you couldn't screen
he couldn't screen
we couldn't screen
you couldn't screen
they couldn't screen 	I couldn't be screening
you couldn't be screening
he couldn't be screening
we couldn't be screening
you couldn't be screening
they couldn't be screening	I couldn't have screened
you couldn't have screened
he couldn't have screened
we couldn't have screened
you couldn't have screened
they couldn't have screened	I couldn't have been screening
you couldn't have been screening
he couldn't have been screening
we couldn't have been screening
you couldn't have been screening
they couldn't have been screening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I screen?
couldn't you screen?
couldn't he screen?
couldn't we screen?
couldn't you screen?
couldn't they screen? 	couldn't I be screening?
couldn't you be screening?
couldn't he be screening?
couldn't we be screening?
couldn't you be screening?
couldn't they be screening? 	couldn't I have screened?
couldn't you have screened?
couldn't he have screened?
couldn't we have screened?
couldn't you have screened?
couldn't they have screened? 	couldn't I have been screening?
couldn't you have been screening?
couldn't he have been screening?
couldn't we have been screening?
couldn't you have been screening?
couldn't they have been screening?