YOU SAID:
my friend ate his jello cookie
INTO JAPANESE
私の友人は彼のゼリークッキーを食べました
BACK INTO ENGLISH
My friend ate his jelly cookie
INTO JAPANESE
友達がゼリークッキーを食べました
BACK INTO ENGLISH
My friend ate a jelly cookie
INTO JAPANESE
友達がゼリークッキーを食べました
BACK INTO ENGLISH
My friend ate a jelly cookie
That didn't even make that much sense in English.