Why do silent letters exist?

One of the trickiest road blocks to learning the English language is the conundrum of silent letters. They take common words and turn them into a confusing mess, inducing anxiety when it comes time to read them aloud.

Considering how the English language and its vernacular has evolved over the past centuries, it raises the question of why silent letters haven’t long been dropped yet.

Auxiliary vs dummy letters

There are two main categories that silent letters fall under: auxiliary letters and dummy letters.

Auxiliary letters come together to form a unique sound. Think of the “chuh” sound formed by joining c and h. This is further divided into two sub-groups, exocentric and endocentric. Exocentric (with the prefix exo- meaning external or outside) means a new sound is created from the two letters. King isn’t pronounced k-eeng, but instead the ki syllable sounds like kih. Then isn’t pronounced with an individual pronunciation for t and h but instead they come together to form the th syllable. Endocentric (endo- meaning within) letters have straightforward pronunciations, like the double m’s in roommate.

These auxiliary letters are still considered silent letters, because you’re not pronouncing each letter individually. You’re combining the letters to form new sounds.

The aptly-named dummy letters, on the other hand, refer to letters that make no sound. These are also divided into two subgroups, inert and empty. Inert refers to words that contain silent letters in one variation but not in others. For example, the g in sign is silent but in the variant signature, it isn’t. Empty letters are always silent, regardless of its variations, like the words island and isle.

Pronunciation evolution

Clear as mud, right? Why do these various forms of silent letters even exist?

Turns out, especially in the case of auxiliary letters, silent letters weren’t always so silent. When the words were first coined, the letters were pronounced. The most popular example of this is the word knight. The k and gh were pronounced — phonetically as in ke-nee-g-htt.

Then, the Great Vowel Shift took place and, over time, pronunciations changed but spellings didn’t catch up.

With dummy letters, it’s pretty much a case of signaling word origins and cultural influences.

Ned Halley, in his book Dictionary of Modern English Grammar, wrote:

As the influence of the Classical world was revived in the 15th century, scholars of English desired to remind their readers that most of the words in the language originated in Latin and Greek.

To show off their knowledge that ‘doubt’, then spelled 'dout' because it came into medieval English via French doute, derived originally from Latin dubitare they added the b — and it stuck.

In its way, it was a nationalistic gesture, reasserting the Classical origins of English over Dutch, French, German and Norse influences of the intervening millennium since Roman influence waned in Britain from the fifth century and Anglo-Saxon languages began to infiltrate.

So people in positions of power (read: printing presses) used their position to add in extra letters to words just because they could. In a time when the language was far from standardized, this was a fairly easy feat to accomplish.

As language continues to evolve, maybe we’ll see the same with spelling. Similar to the Great Vowel Shift, let’s hope we see a Letter Dropping Era so the kids of tomorrow don’t have to ask themselves why silent letters exist any time they misspell a word like knife.