YOU SAID:

once upon time a duck died

INTO JAPANESE

昔々アヒルが死んだ

BACK INTO ENGLISH

Once upon a time the duck died

INTO JAPANESE

昔々、アヒルが死んだ

BACK INTO ENGLISH

Once upon a time, the duck died

INTO JAPANESE

昔々、アヒルは死にました

BACK INTO ENGLISH

Once upon a time, the duck died