I could superscribe you could superscribe she could superscribe we could superscribe you could superscribe they could superscribe
V-ing form
I could be superscribing you could be superscribing she could be superscribing we could be superscribing you could be superscribing they could be superscribing
Perfect
I could have superscribed you could have superscribed she could have superscribed we could have superscribed you could have superscribed they could have superscribed
V-ing perfect
I could have been superscribing you could have been superscribing she could have been superscribing we could have been superscribing you could have been superscribing they could have been superscribing
Negation
Simple form
I couldn't superscribe you couldn't superscribe she couldn't superscribe we couldn't superscribe you couldn't superscribe they couldn't superscribe
V-ing form
I couldn't be superscribing you couldn't be superscribing she couldn't be superscribing we couldn't be superscribing you couldn't be superscribing they couldn't be superscribing
Perfect
I couldn't have superscribed you couldn't have superscribed she couldn't have superscribed we couldn't have superscribed you couldn't have superscribed they couldn't have superscribed
V-ing perfect
I couldn't have been superscribing you couldn't have been superscribing she couldn't have been superscribing we couldn't have been superscribing you couldn't have been superscribing they couldn't have been superscribing
Interrogative form
Simple form
could I superscribe? could you superscribe? could she superscribe? could we superscribe? could you superscribe? could they superscribe?
V-ing form
could I be superscribing? could you be superscribing? could she be superscribing? could we be superscribing? could you be superscribing? could they be superscribing?
Perfect
could I have superscribed? could you have superscribed? could she have superscribed? could we have superscribed? could you have superscribed? could they have superscribed?
V-ing perfect
could I have been superscribing? could you have been superscribing? could she have been superscribing? could we have been superscribing? could you have been superscribing? could they have been superscribing?
Interro-negative form
Simple form
couldn't I superscribe? couldn't you superscribe? couldn't she superscribe? couldn't we superscribe? couldn't you superscribe? couldn't they superscribe?
V-ing form
couldn't I be superscribing? couldn't you be superscribing? couldn't she be superscribing? couldn't we be superscribing? couldn't you be superscribing? couldn't they be superscribing?
Perfect
couldn't I have superscribed? couldn't you have superscribed? couldn't she have superscribed? couldn't we have superscribed? couldn't you have superscribed? couldn't they have superscribed?
V-ing perfect
couldn't I have been superscribing? couldn't you have been superscribing? couldn't she have been superscribing? couldn't we have been superscribing? couldn't you have been superscribing? couldn't they have been superscribing?