YOU SAID:
He is banging his mother's oldest child
INTO JAPANESE
彼は母親の一番上の子を叩いています
BACK INTO ENGLISH
He is beating the mother's top child
INTO JAPANESE
彼は母親の一番上の子をbeっている
BACK INTO ENGLISH
He is the mother's top child
INTO JAPANESE
彼は母親の一番上の子です
BACK INTO ENGLISH
He is the mother's top child
You've done this before, haven't you.