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