YOU SAID:
did you know they did surgery on a grape
INTO JAPANESE
彼らはブドウの手術を知った
BACK INTO ENGLISH
They knew the grape surgery
INTO JAPANESE
彼らはブドウの手術を知っていた
BACK INTO ENGLISH
They knew the operation of grapes
INTO JAPANESE
彼らはブドウの操作を知っていた
BACK INTO ENGLISH
They knew of grape
INTO JAPANESE
彼らはブドウの知っていた
BACK INTO ENGLISH
They knew of the grape
INTO JAPANESE
彼らはブドウの知っていた
BACK INTO ENGLISH
They knew of the grape
That didn't even make that much sense in English.