I must butterfly you must butterfly he must butterfly we must butterfly you must butterfly they must butterfly
V-ing form
I must be butterflying you must be butterflying he must be butterflying we must be butterflying you must be butterflying they must be butterflying
Perfect
I must have butterflied you must have butterflied he must have butterflied we must have butterflied you must have butterflied they must have butterflied
V-ing perfect
I must have been butterflying you must have been butterflying he must have been butterflying we must have been butterflying you must have been butterflying they must have been butterflying
Negation
Simple form
I must not butterfly you must not butterfly he must not butterfly we must not butterfly you must not butterfly they must not butterfly
V-ing form
I must not be butterflying you must not be butterflying he must not be butterflying we must not be butterflying you must not be butterflying they must not be butterflying
Perfect
I must not have butterflied you must not have butterflied he must not have butterflied we must not have butterflied you must not have butterflied they must not have butterflied
V-ing perfect
I must not have been butterflying you must not have been butterflying he must not have been butterflying we must not have been butterflying you must not have been butterflying they must not have been butterflying
Interrogative form
Simple form
must I butterfly? must you butterfly? must he butterfly? must we butterfly? must you butterfly? must they butterfly?
V-ing form
must I be butterflying? must you be butterflying? must he be butterflying? must we be butterflying? must you be butterflying? must they be butterflying?
Perfect
must I have butterflied? must you have butterflied? must he have butterflied? must we have butterflied? must you have butterflied? must they have butterflied?
V-ing perfect
must I have been butterflying? must you have been butterflying? must he have been butterflying? must we have been butterflying? must you have been butterflying? must they have been butterflying?
Interro-negative form
Simple form
must I not butterfly? must you not butterfly? must he not butterfly? must we not butterfly? must you not butterfly? must they not butterfly?
V-ing form
must I not be butterflying? must you not be butterflying? must he not be butterflying? must we not be butterflying? must you not be butterflying? must they not be butterflying?
Perfect
must I not have butterflied? must you not have butterflied? must he not have butterflied? must we not have butterflied? must you not have butterflied? must they not have butterflied?
V-ing perfect
must I not have been butterflying? must you not have been butterflying? must he not have been butterflying? must we not have been butterflying? must you not have been butterflying? must they not have been butterflying?