YOU SAID:

beware of person behind the door

INTO JAPANESE

ドアの向こうにいる人に注意してください

BACK INTO ENGLISH

Be careful with the person behind the door

INTO JAPANESE

ドアの向こう側の人に気を付けて

BACK INTO ENGLISH

Watch out for the people behind the door

INTO JAPANESE

ドアの向こう側の人々に気をつけろ

BACK INTO ENGLISH

Watch out for people behind the door

INTO JAPANESE

ドアの向こう側の人々に気をつけろ

BACK INTO ENGLISH

Watch out for people behind the door