December 01, 2005

An ivory-billed relative clause

Matthew Hutson wrote me (a while ago, actually, back at the beginning of September) to ask this:

I'm aware of the general Language Log consensus on the which/that "rule": which is acceptable in most places where adherents to the rule would argue that is required. But what about the rare reverse case:

"The key point, that all the popular reports missed, is that FOXP2 is a transcription factor..." ( ~myl/ languagelog/ archives/ 002456.html)

Would which — or else the removal of the commas, depending on what he meant — be required here?


Great question. The answer is no, it's not wrong; no correction is needed; but it is true that the subordinator that is now fantastically rare in the role of introducing what The Cambridge Grammar calls a supplementary relative (a more traditional name for them is "appositive" or "non-restrictive" relative clauses). It used to be more common (Jespersen's grammar cites a few), but today you have to hunt around for months and months to find a single example, and it could be years. But Matt has spotted one. The sentence he quotes, which I quoted from an article about the FOXP2 gene in a post I didn't want to interrupt in order to comment, is a genuine case of a recent modern English supplementary relative clause introduced by that. Treasure it, Matt. It's like spotting the syntactic analog of an ivory-billed woodpecker.

Some rather grouchy email from a couple of correspondents suggests to me that I should clarify at least three things about the above.

  1. The example is not a perfect sighting of the ivory-bill; it's just a blurred video frame. Ideally you should be able to tell from the syntax of the construction that it can't be anything other than a supplementary relative. This is sometimes possible, but not here. The example could just be referring to the key point that all the popular reports missed, and putting in commas erroneously. But my reading of the context of the original was that he was saying that the key point was that FOXP2 is a transcription factor, and all the popular reports had missed that — not merely that this was the key point from among those that the popular reports had missed, but that it was the key point. If I'm right, then this is a supplementary relative. [Update, December 4: And I am right. I contacted the author of the sentence, Alec MacAndrew, and asked him what sense he had in mind when he wrote the article in question. He has kindly confirmed that I correctly divined his intention: he did indeed intend the supplementary semantics, where the meaning is "The key point — and incidentally, all the popular reports missed it — is that FOXP2 is a transcription factor". So we do have a genuine observation here.]
  2. The reason I don't simply say that with an occurrence rate that low the construction is simply ungrammatical is just that I'm conservative enough to think that the language changes only slowly and we shouldn't be hurrying it up. Supplementary relatives with that are now extremely rare, but not totally impossible to find. Though I will add this: if teachers taught foreign students that they were simply not grammatical at all, and copy-editors refused to allow them to reach print, they would not be far wrong, and it would do no great harm. (This is not the case with restrictive relatives with which; those are very common, and to teach that they are ungrammatical would be tantamount to lying to the students.)
  3. But you certainly can't use that to introduce a supplementary relative clause if the head noun is human; it is totally ungrammatical: *I asked Vice Chancellor Bradshaw, that I have known for many years, whether he agreed. Even examples such as these used to occur, around a hundred years ago, but I don't think they could be regarded as anything other than a mistake today.
Posted by Geoffrey K. Pullum at December 1, 2005 05:28 PM