Since then, our anxieties about tone seem to have skipped right over the content of our messages to the characters that end them. There has been a long parade of replacements for the period. The writer of that New Republic piece thought ellipses were nice. (They’re not; younger people find them not only Boomerish but also horror-movie ominous.) For a while, young people preferred the nervous chuckling of a “lol” or “haha.” (“Why Do Millennials Feel Compelled to Write ‘Lol’ After Everything?” asked Huffpost last fall — to which one answered that it was “like a tension-breaking mechanism,” while another pointed out that texting “I think I love you, lol” allows you to pretend you were kidding if you don’t get a favorable response.) Emoji, too, had their turn as sentence-enders — all except that subset, like the thumbs-up and the “OK” hand signal, that came to be associated with the same passive-aggressive terseness as the period, the equivalent of a clipped verbal “fine.”