Here's the breakdown:
* Old English: *cnawan* (to know)
* Proto-Germanic: *knawan* (to know)
The word "knowledge" itself is a later development, formed by combining the noun *cnawan* with the suffix "-ledge", which indicates "state of" or "quality of".
Interestingly, the word "know" itself is also directly derived from the Old English *cnawan*. This shared root highlights the close connection between the concepts of "knowing" and "knowledge".