“I BELIEVE THE children are our future,” sang Whitney Houston, making an obvious fact of life sound like a bold claim. Children will of course not only inherit the world, but shape it. And in their linguistic mistakes, their parents can get a sense of how.

Take the child collecting different kinds of animals in a video game: “I got a new specie!”, he cries. The source of the mistake is obvious. The child has heard the slightly rarefied word “species” and assumed it was the plural of something called a specie. Children do this kind of thing all the time as they learn language; generalising from things previously heard and rules previously mastered is the only way they can progress with such speed. In most cases, errors disappear on their own.

Yet tempting, specie-type mistakes happen not just among children, but their parents too. Some survive, and even thrive, until they displace an old form and become the new standard. Few English-speakers today know it, but there was once no such thing as a pea. People ate a mass of boiled pulses called pease. But just as with specie, at some point English people misanalysed pease as a plural, and the new singular pea was born. The same thing happened with cherry, from the Norman cherise, and caper (the edible kind), from the Latin capparis, both singular.

Another kind of confusion happens at the beginning of words. People once worked with a protective bit of clothing called a napron. But enough heard it as “an apron” that apron eventually supplanted napron completely. Other words beginning with vowels and preceded by “an” went through the same process: nadder became adder and nauger, auger (a tool for boring holes). In other instances, an n was added, not subtracted, by a mistake in the opposite direction: a newt was once a ewt, and a nickname was once an eke-name. (Eke is an old word for “also”.) Not all such forms survived: while neilond, nangry and nuncle appear in older English texts, they never did replace island, angry and uncle.

Foreign borrowings are also a source of error-induced change. The French la munition was misunderstood by English-speakers with shaky French as l’ammunition, giving rise to the English word. English-speakers are not the only people who do this kind of thing, nor is French the only victim. The Arabic al-, meaning “the”, has been taken as an integral part of words borrowed from that tongue. So European languages are filled with alkali, algebra and the like. It is as if English had swallowed la munition whole as “lamunition”.

Sometimes borrowings are mangled not because their structure is misunderstood, but their meaning. A chef de cuisine, as it was originally adopted from French, was boss of the kitchen. Chef still means “boss” in French, but the English eventually took a chef to be a cook. Pariah trod a similarly improbable path: the word means “drummer” in Tamil, becoming the name of a downtrodden ethnic group which often performed ceremonial drumming. That “downtrodden” element of the meaning then became the only one in English.

The “pariah” example is instructive. This isn’t so much a word born of a single clear-cut mistake, as one that emerged from a gradual transformation: from drummer to outcast drummers to outcast, each step is short and intelligible. Only to Tamils might the English sense of “pariah” seem wrong. In English, “outcast” really is its meaning.

Every word is changing a little bit, all the time. Look at a few lines of Middle English, and it is nigh impossible to find words that have not altered in spelling, pronunciation, meaning, grammar—or all four. Consider Old English, and those rare examples become nearly zero. Even Shakespeare requires some practice to understand fully.

Many of the tweaks that have made those bygone Englishes into modern English could be seen as an “error” of some sort. Some such changes were systematic: all words with the same vowel gradually being pronounced with a different one, say. Others have affected just one word at a time, and so tend to be too subtle to catch the eye.

The naprons of the world are notable, then, not because they are exceptions, but because they are instances of a common phenomenon—language change through “error”—that happened conspicuously enough to make a tidy example. But modern English is deformed Old English and degenerate Middle English. In other words, like any living language, it is “error” all the way down.