YOU SAID:

My favorite thing is the piano and my favorite person is my sister.

INTO JAPANESE

私の好きなものはピアノで、私の好きな人は私の妹です。

BACK INTO ENGLISH

My favorite is the piano and my favorite is my sister.

INTO JAPANESE

私のお気に入りはピアノで、私のお気に入りは妹です。

BACK INTO ENGLISH

My favorite is the piano and my favorite is my sister.