YOU SAID:
Where did you put my phone?
INTO JAPANESE
自分の携帯電話をどこに置きましたか。
BACK INTO ENGLISH
Where did you put my cell phone?
INTO JAPANESE
私の携帯電話をどこに置きましたか。
BACK INTO ENGLISH
Where did you put my cell phone?
That didn't even make that much sense in English.