YOU SAID:
My friend Ariunbat is boring
INTO JAPANESE
私の友人Ariunbatは退屈です
BACK INTO ENGLISH
My friend Ariunbat is bored
INTO JAPANESE
私の友人Ariunbatは退屈しています
BACK INTO ENGLISH
My friend Ariunbat is bored
That didn't even make that much sense in English.