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