YOU SAID:

you need to go eat a piece of grass

INTO JAPANESE

あなたは草の部分を食べに行く必要があります

BACK INTO ENGLISH

You need to go to eat the part of the grass

INTO JAPANESE

あなたは草の一部を食べに行く必要があります

BACK INTO ENGLISH

You need to go to eat some of the grass

INTO JAPANESE

あなたは草のいくつかを食べに行く必要があります

BACK INTO ENGLISH

You need to go to eat some of the grass