I could bore you could bore he could bore we could bore you could bore they could bore
V-ing form
I could be boring you could be boring he could be boring we could be boring you could be boring they could be boring
Perfect
I could have bored you could have bored he could have bored we could have bored you could have bored they could have bored
V-ing perfect
I could have been boring you could have been boring he could have been boring we could have been boring you could have been boring they could have been boring
Negation
Simple form
I couldn't bore you couldn't bore he couldn't bore we couldn't bore you couldn't bore they couldn't bore
V-ing form
I couldn't be boring you couldn't be boring he couldn't be boring we couldn't be boring you couldn't be boring they couldn't be boring
Perfect
I couldn't have bored you couldn't have bored he couldn't have bored we couldn't have bored you couldn't have bored they couldn't have bored
V-ing perfect
I couldn't have been boring you couldn't have been boring he couldn't have been boring we couldn't have been boring you couldn't have been boring they couldn't have been boring
Interrogative form
Simple form
could I bore? could you bore? could he bore? could we bore? could you bore? could they bore?
V-ing form
could I be boring? could you be boring? could he be boring? could we be boring? could you be boring? could they be boring?
Perfect
could I have bored? could you have bored? could he have bored? could we have bored? could you have bored? could they have bored?
V-ing perfect
could I have been boring? could you have been boring? could he have been boring? could we have been boring? could you have been boring? could they have been boring?
Interro-negative form
Simple form
couldn't I bore? couldn't you bore? couldn't he bore? couldn't we bore? couldn't you bore? couldn't they bore?
V-ing form
couldn't I be boring? couldn't you be boring? couldn't he be boring? couldn't we be boring? couldn't you be boring? couldn't they be boring?
Perfect
couldn't I have bored? couldn't you have bored? couldn't he have bored? couldn't we have bored? couldn't you have bored? couldn't they have bored?
V-ing perfect
couldn't I have been boring? couldn't you have been boring? couldn't he have been boring? couldn't we have been boring? couldn't you have been boring? couldn't they have been boring?