Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I must piggy you must piggy he must piggy we must piggy you must piggy they must piggy
V-ing form
I must be piggying you must be piggying he must be piggying we must be piggying you must be piggying they must be piggying
Perfect
I must have piggied you must have piggied he must have piggied we must have piggied you must have piggied they must have piggied
V-ing perfect
I must have been piggying you must have been piggying he must have been piggying we must have been piggying you must have been piggying they must have been piggying
Negation
Simple form
I must not piggy you must not piggy he must not piggy we must not piggy you must not piggy they must not piggy
V-ing form
I must not be piggying you must not be piggying he must not be piggying we must not be piggying you must not be piggying they must not be piggying
Perfect
I must not have piggied you must not have piggied he must not have piggied we must not have piggied you must not have piggied they must not have piggied
V-ing perfect
I must not have been piggying you must not have been piggying he must not have been piggying we must not have been piggying you must not have been piggying they must not have been piggying
Interrogative form
Simple form
must I piggy? must you piggy? must he piggy? must we piggy? must you piggy? must they piggy?
V-ing form
must I be piggying? must you be piggying? must he be piggying? must we be piggying? must you be piggying? must they be piggying?
Perfect
must I have piggied? must you have piggied? must he have piggied? must we have piggied? must you have piggied? must they have piggied?
V-ing perfect
must I have been piggying? must you have been piggying? must he have been piggying? must we have been piggying? must you have been piggying? must they have been piggying?
Interro-negative form
Simple form
must I not piggy? must you not piggy? must he not piggy? must we not piggy? must you not piggy? must they not piggy?
V-ing form
must I not be piggying? must you not be piggying? must he not be piggying? must we not be piggying? must you not be piggying? must they not be piggying?
Perfect
must I not have piggied? must you not have piggied? must he not have piggied? must we not have piggied? must you not have piggied? must they not have piggied?
V-ing perfect
must I not have been piggying? must you not have been piggying? must he not have been piggying? must we not have been piggying? must you not have been piggying? must they not have been piggying?