The silent /K/ occurs before the letter n in most cases,

e.g. Knife , knot, Knee, know, Knowledge, Knight ,etc. There are some exceptions which are too few to bother with.

The Kn combination comes from the Germanic languages where the K is still pronounced in some words.

Before the 17th century people in England also pronounced words like Knee, and Knife using the /k/ sound  .However, over time, and for whatever reason, the /k/ sound became silent, probably because it was too awkward to pronounce.

There are many advantages to having silent letters in English, and one is that different spellings can help us to differentiate between homophones which are words that are spelt differently, but have the same sound. e.g. night and Knight. The silent e at the end of words also gives us a clue as to how to pronounce preceding vowels.

Finally, many English spellings are weird because of our history. Our alphabet has a limited number of letters and therefore couldn't accommodate the influx of new sounds and words brought in by invaders over the centuries.

The silent ⟨K⟩ occurs before the letter ⟨N⟩ in most cases,

e.g. Knife , knot, knee, know, knowledge, knight etc. There are some exceptions which are too few to bother with.

The ⟨kn⟩ combination comes from the Germanic languages where the K is still pronounced in some words.

Before the 17th century people in England also pronounced words like knee, and knife using the /k/ sound. However, over time, and for whatever reason, the /k/ sound became silent, probably because it was too awkward to pronounce.

There are many advantages to having silent letters in English, and one is that different spellings can help us to differentiate between homophones which are words that are spelt differently, but have the same sound. e.g. night and Knight.

The silent e at the end of words also gives us a clue as to how to pronounce preceding vowels.

Finally, many English spellings are weird because of our history. Our alphabet has a limited number of letters and therefore couldn't accommodate the influx of new sounds and words brought in by invaders over the centuries.

^{⟨Angled brackets⟩ represent orthography (spelling) while /slashes/ represent sounds}