YOU SAID:
Hi person, I don't know
INTO JAPANESE
こんにちは、私は知りません
BACK INTO ENGLISH
hello, i don't know
INTO JAPANESE
こんにちは、わかりません
BACK INTO ENGLISH
Hello, I don't understand
INTO JAPANESE
こんにちは、わかりません
BACK INTO ENGLISH
Hello, I don't understand
You've done this before, haven't you.