YOU SAID:
slip the paper inside the folder
INTO JAPANESE
フォルダーの中に紙を入れる
BACK INTO ENGLISH
Put paper in the folder
INTO JAPANESE
紙をフォルダーに入れる
BACK INTO ENGLISH
Put paper in a folder
INTO JAPANESE
紙をフォルダーに入れる
BACK INTO ENGLISH
Put paper in a folder
That didn't even make that much sense in English.