A WORD, PLEASE:Irregular past tenses can be tricky

According to a new study, people with Tourette Syndrome may have better mental grammar skills than normal people. This is terrible news. Not for them. For me.

How am I, a dyed-in-the-wool smart aleck, supposed to report this important grammar-related news without stooping to making cheap Tourette jokes? Clearly I can’t. So my only hope is to quickly explain the highlights of the researchers’ findings then move on to a related grammar lesson.

The study, conducted by the Georgetown University Medical Center and the Kennedy Krieger Institute, starts off by pointing out that, contrary to what I once learned from an episode of “L.A. Law,” the cussing brand of Tourette is actually very rare.

The disorder is more often characterized by physical tics, and could exist in mild forms in up to 10% of the population.

The involuntary use of obscene words, which is only rarely associated with Tourette, is called “coprolalia.” And just when I thought I could maintain my professionalism here, I made the terrible mistake of looking up “coprolalia.” According to Wikipedia, this word was formed when someone took the Greek “lalia” meaning “babbling” or “meaningless talk” and paired it up with the Greek “copro” — which means something so surprisingly graphic I’m afraid to write it here. (Think digestive system. Think “talking trash” rephrased as “talking waste.” Think politicians at election time.)

Moving on.

For the study, researchers distinguished between two types of grammar learning: “rule-governed learning,” which is part of something called the “procedural memory system,” allows us to combine parts of words to form regular past tenses. We add “ed” to “walk” to get “walked.”

The other type of learning, called “idiosyncratic knowledge” and associated with what’s called “declarative memory,” governs our ability to learn irregular past tense forms such as “brought” and “shook.”

Researchers found that “children with Tourette Syndrome were significantly faster than the control group in producing rule-governed past tenses (like slip-slipped) that depend on grammar and procedural memory but not in producing irregular or other unpredictable past tenses (such as bring-brought) that are stored in declarative memory,” as was reported July 16 in “Medical Condition News.”

There are many ways to interpret this new study, but I choose to interpret it like this: Even people who are great at forming regular past tenses can get tripped up by irregulars. And that would explain why some of them seem to elude everyone.

Take a word like “slay.” Once upon a time, I worked at a newspaper that printed the headline like, “Officer slayed on duty.” We got a letter from a reader: There is no “slayed,” he said. And he was right.

What we wanted was the past participle, “slain” or perhaps in another context we would have wanted the simple past tense, “slew.”

You likely knew that already, so I’ll throw some tougher ones your way. How about the past tense and past particle of the verb “cleave,” as in “I cleave this tree stump with an ax.” No, it’s not “cleaved.” The correct forms are, “Yesterday I cleft this tree stump” and “In the past I have cleft many tree stumps.”

And take “forbear,” meaning “to refrain from, avoid or cease,” which takes the past tense “forbore” but the past participle “forborne”?

My examples, and my final words to you this week: Today I forbear making any more jokes about Tourette Syndrome or the prefix “copro.” Yesterday I forbore making these bad jokes. In the past I have forborne making them. And we can only hope that, in the future, I will continue to forbear.