YOU SAID:
I'm just walking by to let you know (by to let you know)
INTO JAPANESE
私はあなたに知らせるために歩いています(あなたに知らせるために)
BACK INTO ENGLISH
I am walking to let you know (to let you know)
INTO JAPANESE
私はあなたに知らせるために歩いています(あなたに知らせるために)
BACK INTO ENGLISH
I am walking to let you know (to let you know)
That didn't even make that much sense in English.