YOU SAID:

Do you know who ate all the doughnuts?

INTO JAPANESE

誰がドーナツを全部食べたか知っていますか？

BACK INTO ENGLISH

Do you know who ate all the donuts?

INTO JAPANESE

誰がドーナツを全部食べたのか知っていますか？

BACK INTO ENGLISH

Do you know who ate all the donuts?