YOU SAID:
He bought a doll for his Grandma
INTO JAPANESE
彼はおばあちゃんのために人形を買った
BACK INTO ENGLISH
He bought a doll for his grandmother.
INTO JAPANESE
彼は祖母のために人形を買った。
BACK INTO ENGLISH
He bought a doll for his grandmother.
That didn't even make that much sense in English.