YOU SAID:

I don't know who that was

INTO JAPANESE

それが誰だったのか分かりません

BACK INTO ENGLISH

I don't know who it was

INTO JAPANESE

その後　彼は電話を切った それが誰だか知らない

BACK INTO ENGLISH

I don't know who it was.

INTO JAPANESE

その後　彼は電話を切った それが誰だか知らない

BACK INTO ENGLISH

I don't know who it was.