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