YOU SAID:
i saw her duck the bat
INTO JAPANESE
私は彼女のアヒルがコウモリを見た
BACK INTO ENGLISH
I saw her duck bats
INTO JAPANESE
私は彼女のアヒルのコウモリを見ました
BACK INTO ENGLISH
I saw her duck's bat
INTO JAPANESE
私は彼女のアヒルのコウモリを見ました
BACK INTO ENGLISH
I saw her duck's bat
That didn't even make that much sense in English.