When I’m hiring people for Electric Book Works or Paperight, I know whether they’ll work out the moment I read their cover letter. When I read a really good cover letter, I can essentially ignore the CV attached to it. (Though I do expect the CV to be well constructed, neatly laid out, and error free.)

Why is there such a clear correlation between a well-written cover letter and an excellent team member? Because of what good writing represents.

Writing is a pinnacle skill. In order to write well, you have to have a range of other skills in place first. They are the underlying foundation. Once you have those other skills, good writing represents their combined result: the pinnacle of their positive effects.

When I read a great piece of writing, I know the writer has those foundational skills. In this diagram I only list a few off the top of my head: empathy (which is an appreciation for what your audience is thinking and feeling), attention to detail, a broad general knowledge, logic, clarity of thought, persuasiveness, the ability to critique your own work (also called a crap detector), an appreciation for rules and the smarts to break them, self-discipline, the ability to prioritise, a sensitivity to cliché and stereotype – and more.

As an employer, that’s much of what I’m looking for. (I do, of course, factor in whether a person is writing in their home language, but even then many of the skills of good writing transcend a person’s grasp of grammar.)

Writing is not a bag of skills learned for their own sake – spelling, grammar, punctuation, metaphor, and so on – though sometimes they’re presented that way. In a recent piece in The Atlantic, Jessica Lahey argues that spelling counts because, in a busy world, people need a quick and superficial way to measure you:

you’ve already spent nine hours today reading through these applications. The one in your hand looks pretty much like all those thousands of others. If only there were some way to decide without having to wade through the 500-word essay about the summer spent digging latrines in Kenya…

And there it is — an easy way out, right there in the third sentence: “The days are hot and dry, your thirsty, tired, and homesick.” Not “you’re,” but “your.” The essay may go on to articulate inspired truths about human nature. It may reveal some novel insight that has never been revealed before. But here’s the rub: This admissions officer with the limited time and frustrated spouse is done. Three lines into the essay, the application lands squarely on the “No” pile.

This example tends to upset my students. They wail, “But that’s unfair! Shouldn’t it be the ideas that count? That’s about appearances, not content!” And they are right. Ideas should be judged on substance rather than appearances, but this simply is not how our world works. We live in a society where appearances matter, where in order to be heard and taken seriously we are judged quickly and superficially.

That’s a shame coming from a writing teacher. It reads like an apology: ‘I’m sorry you have to learn this spelling rubbish, but the world’s so silly about these things!’

There is nothing superficial about judging someone on their spelling. Unless you really are stranded on a desert island without a dictionary, the Internet, or a smart friend, a spelling mistake demonstrates a clear lack of fundamental skill or temperament. Misspellings – especially in business documents – are the symptoms of an underlying carelessness that to employers, clients, colleagues, and fans can and should be deeply troubling.

The quality of your writing is a clear indicator of the quality of your mind. And while spelling is only one part of good writing, it’s a crucial one: get it right, and you give your work a chance to shine – and you to shine through it.