Style is subjective, but are the biggest selling children's books in history really ungrammatical? Several otherwise positive reviewers make the same criticism. Grammar may not be Rowling's strong point and she clearly makes what one reviewer calls "wanton use of semi-colons". But her biggest sin by far is habitual use of run-on sentences, which even seven-year-olds are supposed to avoid.
A run-on sentence (also called a "fused sentence" or "comma splice") is one that should be two or more sentences. Consider this from The Order of the Phoenix (page 363): "But twenty-nil was nothing, there was still time for Gryffindor to catch up on catch the Snitch."
Unless they have good reason, no one, least of all a best-selling author read by millions of children, should put main clauses together in one sentence without a conjunction. The comma is not enough to mark the sentence boundary. We need a full stop.
Even in Year 1 term 1, under the literacy strategy pupils should be learning to use full stops to demarcate sentences. In 2003 sample test papers, marks are lost even at KS1 for not marking sentence boundaries correctly; in the KS2 Healthy Snack Shop task, comma splice is specifically penalised.
JK Rowling does not set a good example. Her books are riddled with run-on sentences. In The Order of the Phoenix alone there are dozens. Admittedly, most are in direct speech, and so could in theory be defended as being used for effect. We would, for example, hardly mark down Hagrid's utterances for not being in standard English.
There are, however, just too many instances for this defence to succeed. At times, too, the flaw works against what the context demands; for example in The Prisoner of Azkaban (page 287): "By the time he is human again, it will be too late, Sirius will be worse than dead." The dramatic effect demands a significant pause between "late" and "Sirius", not a mere comma.
I am not anti-Harry. The Potter phenomenon is a contagious but benevolent plague. My daughter infected me, and has passed on the virus to my 16-year-old son, who has read four Potters in two weeks - the first books he has read for pleasure since last summer.
However, I do feel sorry for today's children. They are expected to follow language norms, yet are bombarded with examples of bad practice.
In punctuation, the novelist Margaret Atwood battles with her publishers:
"I trade off a semicolon here, a comma there." But when she departs from the norms, we know a conscious effect is being sought. JK Rowling and publisher Bloomsbury should use "creative" punctuation only when called for, and err on the side of convention.
Then knowledge acquired in schools will not be undermined by children's exposure to this questionable punctuation.
Paul Livesey is a senior lecturer in English language and linguistics, University of Central Lancashire