YOU SAID:
I forgot the key to their neighbors' house
INTO JAPANESE
私は隣人の家の鍵を忘れた
BACK INTO ENGLISH
I forgot the key of my neighbor's house
INTO JAPANESE
私は隣人の家の鍵を忘れた
BACK INTO ENGLISH
I forgot the key of my neighbor's house
Okay, I get it, you like Translation Party.