YOU SAID:
He probably wanted to say good-bye privately.
INTO JAPANESE
彼はたぶん個人的にお別れを言いたいと思っていました。
BACK INTO ENGLISH
He probably wanted to say good-bye personally.
INTO JAPANESE
彼はたぶん個人的にさよならを言いたいと思っていました。
BACK INTO ENGLISH
He probably wanted to say good-bye personally.
That didn't even make that much sense in English.