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