I can vacillate you can vacillate he can vacillate we can vacillate you can vacillate they can vacillate
V-ing form
I can be vacillating you can be vacillating he can be vacillating we can be vacillating you can be vacillating they can be vacillating
Perfect
I can have vacillated you can have vacillated he can have vacillated we can have vacillated you can have vacillated they can have vacillated
V-ing perfect
I can have been vacillating you can have been vacillating he can have been vacillating we can have been vacillating you can have been vacillating they can have been vacillating
Negation
Simple form
I cannot vacillate you cannot vacillate he cannot vacillate we cannot vacillate you cannot vacillate they cannot vacillate
V-ing form
I cannot be vacillating you cannot be vacillating he cannot be vacillating we cannot be vacillating you cannot be vacillating they cannot be vacillating
Perfect
I cannot have vacillated you cannot have vacillated he cannot have vacillated we cannot have vacillated you cannot have vacillated they cannot have vacillated
V-ing perfect
I cannot have been vacillating you cannot have been vacillating he cannot have been vacillating we cannot have been vacillating you cannot have been vacillating they cannot have been vacillating
Interrogative form
Simple form
can I vacillate? can you vacillate? can he vacillate? can we vacillate? can you vacillate? can they vacillate?
V-ing form
can I be vacillating? can you be vacillating? can he be vacillating? can we be vacillating? can you be vacillating? can they be vacillating?
Perfect
can I have vacillated? can you have vacillated? can he have vacillated? can we have vacillated? can you have vacillated? can they have vacillated?
V-ing perfect
can I have been vacillating? can you have been vacillating? can he have been vacillating? can we have been vacillating? can you have been vacillating? can they have been vacillating?
Interro-negative form
Simple form
can I not vacillate? can you not vacillate? can he not vacillate? can we not vacillate? can you not vacillate? can they not vacillate?
V-ing form
can I not be vacillating? can you not be vacillating? can he not be vacillating? can we not be vacillating? can you not be vacillating? can they not be vacillating?
Perfect
can I not have vacillated? can you not have vacillated? can he not have vacillated? can we not have vacillated? can you not have vacillated? can they not have vacillated?
V-ing perfect
can I not have been vacillating? can you not have been vacillating? can he not have been vacillating? can we not have been vacillating? can you not have been vacillating? can they not have been vacillating?