YOU SAID:

i will go to a baseball game, which is for my younger brother

INTO JAPANESE

私は私の弟のためにある野球の試合に行きます

BACK INTO ENGLISH

I go to a baseball game for my brother

INTO JAPANESE

私は私の兄弟のために野球の試合に行きます

BACK INTO ENGLISH

I go to a baseball game for my brothers

INTO JAPANESE

私は私の兄弟のために野球の試合に行きます

BACK INTO ENGLISH

I go to a baseball game for my brothers