YOU SAID:
I saw someone steal my bike
INTO JAPANESE
だれかが私の自転車を盗む見た
BACK INTO ENGLISH
Someone is stealing my bicycle I saw
INTO JAPANESE
私は見た私の自転車を盗み
BACK INTO ENGLISH
I saw my bike to steal
INTO JAPANESE
私は見た私の自転車を盗むために
BACK INTO ENGLISH
I saw my bike to steal
You've done this before, haven't you.