* Old English: The "kn" combination originally represented a single sound, a hard "k" sound. This is why we see words like "knife" and "knee" with "kn" at the beginning.
* Middle English: The sound of "k" before "n" gradually softened, and by the Middle English period, it was often pronounced as just a "n" sound. Think of the word "know," which used to be pronounced with a "k" sound at the beginning.
* Modern English: This sound shift became more pronounced over time, leading to the "kn" being completely silent in many words.
Here are some additional reasons why "kn" became silent:
* Pronunciation Shifts: Languages are constantly evolving, and sounds shift over time. The "kn" sound was one that eventually shifted towards a pure "n" sound.
* Assimilation: In some cases, the "k" sound may have been assimilated into the preceding vowel sound. This means the "k" became part of the vowel sound instead of a separate sound.
Examples:
* Knife: Originally pronounced "k-nife."
* Knee: Originally pronounced "k-nee."
* Know: Originally pronounced "k-now."
While "kn" is silent in many words, it's important to note that it is still pronounced in a few words like "knave" and "knack." This showcases the intricate and ever-evolving nature of language.