I must snowboard you must snowboard he must snowboard we must snowboard you must snowboard they must snowboard
V-ing form
I must be snowboarding you must be snowboarding he must be snowboarding we must be snowboarding you must be snowboarding they must be snowboarding
Perfect
I must have snowboarded you must have snowboarded he must have snowboarded we must have snowboarded you must have snowboarded they must have snowboarded
V-ing perfect
I must have been snowboarding you must have been snowboarding he must have been snowboarding we must have been snowboarding you must have been snowboarding they must have been snowboarding
Negation
Simple form
I must not snowboard you must not snowboard he must not snowboard we must not snowboard you must not snowboard they must not snowboard
V-ing form
I must not be snowboarding you must not be snowboarding he must not be snowboarding we must not be snowboarding you must not be snowboarding they must not be snowboarding
Perfect
I must not have snowboarded you must not have snowboarded he must not have snowboarded we must not have snowboarded you must not have snowboarded they must not have snowboarded
V-ing perfect
I must not have been snowboarding you must not have been snowboarding he must not have been snowboarding we must not have been snowboarding you must not have been snowboarding they must not have been snowboarding
Interrogative form
Simple form
must I snowboard? must you snowboard? must he snowboard? must we snowboard? must you snowboard? must they snowboard?
V-ing form
must I be snowboarding? must you be snowboarding? must he be snowboarding? must we be snowboarding? must you be snowboarding? must they be snowboarding?
Perfect
must I have snowboarded? must you have snowboarded? must he have snowboarded? must we have snowboarded? must you have snowboarded? must they have snowboarded?
V-ing perfect
must I have been snowboarding? must you have been snowboarding? must he have been snowboarding? must we have been snowboarding? must you have been snowboarding? must they have been snowboarding?
Interro-negative form
Simple form
must I not snowboard? must you not snowboard? must he not snowboard? must we not snowboard? must you not snowboard? must they not snowboard?
V-ing form
must I not be snowboarding? must you not be snowboarding? must he not be snowboarding? must we not be snowboarding? must you not be snowboarding? must they not be snowboarding?
Perfect
must I not have snowboarded? must you not have snowboarded? must he not have snowboarded? must we not have snowboarded? must you not have snowboarded? must they not have snowboarded?
V-ing perfect
must I not have been snowboarding? must you not have been snowboarding? must he not have been snowboarding? must we not have been snowboarding? must you not have been snowboarding? must they not have been snowboarding?