YOU SAID:

John had had had had had had Greta's book

INTO JAPANESE

ジョンはグレタの本を持ったことがあったことがありました

BACK INTO ENGLISH

John had had a book on Greta

INTO JAPANESE

ジョンはグレタに関する本を持っていた

BACK INTO ENGLISH

John had a book about Greta

INTO JAPANESE

ジョンはグレタについての本を持っていました

BACK INTO ENGLISH

John had a book about Greta