YOU SAID:

I left my phone on the left side of the room.

INTO JAPANESE

私は自分の電話を部屋の左側に置いた。

BACK INTO ENGLISH

I put my phone on the left side of the room.

INTO JAPANESE

私は自分の電話を部屋の左側に置いた。

BACK INTO ENGLISH

I put my phone on the left side of the room.