English verb conjugation
COULD RIBBOR

Regular verb: ribbor - ribbored - ribbored

Affirmation

Simple form	V-ing form
I could ribbor you could ribbor he could ribbor we could ribbor you could ribbor they could ribbor	I could be ribboring you could be ribboring he could be ribboring we could be ribboring you could be ribboring they could be ribboring
Perfect	V-ing perfect
I could have ribbored you could have ribbored he could have ribbored we could have ribbored you could have ribbored they could have ribbored	I could have been ribboring you could have been ribboring he could have been ribboring we could have been ribboring you could have been ribboring they could have been ribboring

Negation

Simple form	V-ing form
I couldn't ribbor you couldn't ribbor he couldn't ribbor we couldn't ribbor you couldn't ribbor they couldn't ribbor	I couldn't be ribboring you couldn't be ribboring he couldn't be ribboring we couldn't be ribboring you couldn't be ribboring they couldn't be ribboring
Perfect	V-ing perfect
I couldn't have ribbored you couldn't have ribbored he couldn't have ribbored we couldn't have ribbored you couldn't have ribbored they couldn't have ribbored	I couldn't have been ribboring you couldn't have been ribboring he couldn't have been ribboring we couldn't have been ribboring you couldn't have been ribboring they couldn't have been ribboring

Interrogative form

Simple form	V-ing form
could I ribbor? could you ribbor? could he ribbor? could we ribbor? could you ribbor? could they ribbor?	could I be ribboring? could you be ribboring? could he be ribboring? could we be ribboring? could you be ribboring? could they be ribboring?
Perfect	V-ing perfect
could I have ribbored? could you have ribbored? could he have ribbored? could we have ribbored? could you have ribbored? could they have ribbored?	could I have been ribboring? could you have been ribboring? could he have been ribboring? could we have been ribboring? could you have been ribboring? could they have been ribboring?

Interro-negative form

Simple form	V-ing form
couldn't I ribbor? couldn't you ribbor? couldn't he ribbor? couldn't we ribbor? couldn't you ribbor? couldn't they ribbor?	couldn't I be ribboring? couldn't you be ribboring? couldn't he be ribboring? couldn't we be ribboring? couldn't you be ribboring? couldn't they be ribboring?
Perfect	V-ing perfect
couldn't I have ribbored? couldn't you have ribbored? couldn't he have ribbored? couldn't we have ribbored? couldn't you have ribbored? couldn't they have ribbored?	couldn't I have been ribboring? couldn't you have been ribboring? couldn't he have been ribboring? couldn't we have been ribboring? couldn't you have been ribboring? couldn't they have been ribboring?