Autocorrect originated with word processing programs of the 1980s, in which the language used was checked against a dictionary to make sure the spelling was correct. (According to a 2012 study in Britain, two-thirds of adults would not be able to spell “necessary” and one-third “definitely” without the help of the feature.) Back then the point was simple: to make typing faster and more accurate. To help you, you know, not look like an idiot.

But these days autocorrect is creating problems as it solves others. Tech companies like Google, Facebook and Apple employ dozens of linguists — or “natural language programmers,” as they are known — to analyze language patterns and to track slang, even pop culture. And they can do amazing things: correct when you hit the wrong keys (the “fat finger” phenomenon) and analyze whom you are texting, how you have spoken with that person in the past, even what you’ve talked about.

Apple’s iOS 8 operating system, released in September, even purports to know how your tone changes by medium — that is, “the casual style” you may use in texting versus “the more formal language” you are likely to use in email, as the company put it in a statement. It adjusts for whom you are communicating with, knowing that your choice of words with a buddy is probably more laid-back than it would be with your boss.

Your smartphone may now be able to suggest not just words but entire phrases. And the more you use it, the more it remembers, paying attention to repeated words, the structure of your sentences and tone.

All of which is fine, except that it turns the notion of the guiltless autocorrect on its head. These days, autocorrections are likely to tell the person on the receiving end something about you.

“A lot of the time, you can’t even replicate it because it’s so personalized,” said Ben Zimmer, the chairman of the new-words committee at the American Dialect Society, which is devoted to the study of the English language.