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