YOU SAID:
The duck is the best thing in this world
INTO JAPANESE
アヒルはこの世界で最高のものです
BACK INTO ENGLISH
Ducks are the best thing in the world.
INTO JAPANESE
アヒルは世界で最高のものです。
BACK INTO ENGLISH
Ducks are the best thing in the world.
That didn't even make that much sense in English.