English is full of silent letters, but some of them were not always silent.

A thousand years ago, words like knife, knee, and knight were pronounced much closer to the way they were spelled. The k at the beginning was spoken aloud, so knife sounded more like "k-nife" and knee more like "k-nee."

The gh was not silent either. In words such as night, light, and might, it represented a rough, throaty sound similar to the ch in the Scottish word loch.

One of the most dramatic examples is knight. The word comes from the Old English cniht, meaning a boy, servant, or attendant. Nearly every letter was pronounced. Over centuries, English speakers gradually stopped pronouncing the opening k and the guttural gh, but the spelling remained.

The same thing happened to many other words. Pronunciation evolved while spelling changed much more slowly. By the time printing presses helped standardize written English in the late 1400s, many of these sound changes were already underway.

As a result, modern English still carries clues to how people spoke hundreds of years ago.

Open an English dictionary and you are looking at a museum of old pronunciations. The silent letters survived long after the sounds themselves faded away.