YOU SAID:

ill burn that bridge when i come to it

INTO JAPANESE

私がそれに来ると病気はその橋を燃やす

BACK INTO ENGLISH

I will burn the bridge if I come to it

INTO JAPANESE

私がそれに来るなら、私は橋を燃やすだろう

BACK INTO ENGLISH

If I come to it, I will burn the bridge

INTO JAPANESE

私がそれに来るならば、私は橋を燃やすだろう

BACK INTO ENGLISH

If I come to it, I will burn the bridge