English verb conjugation
COULD GREATEN

Regular verb: greaten - greatened - greatened

Affirmation

Simple form	V-ing form
I could greaten you could greaten he could greaten we could greaten you could greaten they could greaten	I could be greatening you could be greatening he could be greatening we could be greatening you could be greatening they could be greatening
Perfect	V-ing perfect
I could have greatened you could have greatened he could have greatened we could have greatened you could have greatened they could have greatened	I could have been greatening you could have been greatening he could have been greatening we could have been greatening you could have been greatening they could have been greatening

Negation

Simple form	V-ing form
I couldn't greaten you couldn't greaten he couldn't greaten we couldn't greaten you couldn't greaten they couldn't greaten	I couldn't be greatening you couldn't be greatening he couldn't be greatening we couldn't be greatening you couldn't be greatening they couldn't be greatening
Perfect	V-ing perfect
I couldn't have greatened you couldn't have greatened he couldn't have greatened we couldn't have greatened you couldn't have greatened they couldn't have greatened	I couldn't have been greatening you couldn't have been greatening he couldn't have been greatening we couldn't have been greatening you couldn't have been greatening they couldn't have been greatening

Interrogative form

Simple form	V-ing form
could I greaten? could you greaten? could he greaten? could we greaten? could you greaten? could they greaten?	could I be greatening? could you be greatening? could he be greatening? could we be greatening? could you be greatening? could they be greatening?
Perfect	V-ing perfect
could I have greatened? could you have greatened? could he have greatened? could we have greatened? could you have greatened? could they have greatened?	could I have been greatening? could you have been greatening? could he have been greatening? could we have been greatening? could you have been greatening? could they have been greatening?

Interro-negative form

Simple form	V-ing form
couldn't I greaten? couldn't you greaten? couldn't he greaten? couldn't we greaten? couldn't you greaten? couldn't they greaten?	couldn't I be greatening? couldn't you be greatening? couldn't he be greatening? couldn't we be greatening? couldn't you be greatening? couldn't they be greatening?
Perfect	V-ing perfect
couldn't I have greatened? couldn't you have greatened? couldn't he have greatened? couldn't we have greatened? couldn't you have greatened? couldn't they have greatened?	couldn't I have been greatening? couldn't you have been greatening? couldn't he have been greatening? couldn't we have been greatening? couldn't you have been greatening? couldn't they have been greatening?