YOU SAID:
I never knew that your head was hollow
INTO JAPANESE
あなたの頭がくぼんでいるなんて知らなかった
BACK INTO ENGLISH
I didn't know your head was hollow
INTO JAPANESE
あなたの頭がくぼんでいるなんて知らなかった
BACK INTO ENGLISH
I didn't know your head was hollow
That didn't even make that much sense in English.