YOU SAID:

If I die this is the reason

INTO JAPANESE

私が死ぬならこれが理由です

BACK INTO ENGLISH

This is the reason if I die

INTO JAPANESE

これは私が死ぬ場合の理由です

BACK INTO ENGLISH

This is the reason why I die

INTO JAPANESE

これが私が死ぬ理由です

BACK INTO ENGLISH

This is why I die

INTO JAPANESE

これが私が死ぬ理由です

BACK INTO ENGLISH

This is why I die