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