could screen
Regular verb: screen - screened- screened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could screen
you could screen
she could screen
we could screen
you could screen
they could screen 	I could be screening
you could be screening
she could be screening
we could be screening
you could be screening
they could be screening	I could have screened
you could have screened
she 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
she 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
she 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
she 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
she 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
she 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 she screen?
could we screen?
could you screen?
could they screen? 	could I be screening?
could you be screening?
could she be screening?
could we be screening?
could you be screening?
could they be screening? 	could I have screened?
could you have screened?
could she 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 she 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 she 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 she 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 she 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 she have been screening?
couldn't we have been screening?
couldn't you have been screening?
couldn't they have been screening?