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