Complaining about poor grammar in literature is a loser’s game. No one likes a grammar bore, for one thing, and the rules of language are constantly morphing, for another. Still, someone has to say it: The grammar in children’s books can be surprisingly careless. “We’re drawn to each other, us messengers,” reads the first line in the forthcoming young-adult novel, “The Messengers,” by Edward Hogan. A third grader could tell you that “we messengers” is needed.

Children who grow up reading books that validate poor grammar and usage may become teenagers who have trouble understanding what ails their sentences and later, as adults, be mystified when their resume go unacknowledged. Certainly many adults know the slight gust of disappointment that comes when a person we admire says, for example, “her and I.” You’d think that writers for children, of all people, would take pains to get things right.

For the younger set, the most notorious exponent of grammatical no-no’s remains Barbara Parks, the late author of the many Junie B. Jones books. Some parents and librarians deprecate these slim volumes because of Junie’s bad grammar and poor spelling, but the linguistic license they take (and the sympathetic, humorous stories they tell) is hugely popular with 5- to 8-year-olds. That children of this age are just learning to spell and write adds to the irony; while one set of adults is trying to persuade them that the past tense of “run” is “ran,” little Junie B. gaily uses “runned.” Plenty of young readers will be in on the joke, but you have to wonder if some aren’t a little confused. If it is in print, it must be right—right?

A certain cohort of lightly illustrated, fast-paced stories for 11- to 14-year-olds, particularly boys, tend to feature loose, jaunty writing that would never pass muster in the classroom. “She has like 183 million Instagram followers,” explains eighth-grader Wyatt Palmer of the girl he adores in “The Worst Class Trip Ever” (Disney-Hyperion, 214 pages, $13.99) a laugh-out-loud caper full of “gonna’s” and “dunno’s” by the very funny Dave Barry. Involving droning chaperones, stinky classmates, tattooed foreigners and stolen military hardware, Wyatt’s adventure on a school trip to Washington unfurls with verve and humor. (Mr. Barry even gives a cameo to Washington Post writer Gene Weingarten, who, as the author of last year’s “Me & Dog,” is a known language criminal.) Occasional illustrations by Jon Cannell add to the cheerful nuttiness of Wyatt’s story, which surely would be just as entertaining written in more careful English.

The same goes for the work of the amusing Tom Angleberger, author of the best-selling “Origami Yoda” books whose latest, “The Rat With the Human Face” (Amulet, 146 pages, $12.95) contains such offenses as adjectives used as adverbs and the always-tempting “me” when correct usage calls for “I.” This sequel to “Poop Fountain!” (2014) also contains, it must be said, an engaging, goofy and occasionally poignant account—told through handwritten notes and diary entries—of a madcap escapade that gets three middle-school friends into trouble.