YOU SAID:

you mustn't polish spectacles with black shoe polish

INTO JAPANESE

あなたは黒い靴磨きで眼鏡を磨いてはいけません

BACK INTO ENGLISH

You should not brush your glasses with black shoe polish

INTO JAPANESE

あなたは黒の靴磨きであなたの眼鏡を磨くべきではありません

BACK INTO ENGLISH

You should not brush your glasses with black shoe polish