"...During the commercial, the voice-over person says "teeth whitening." Shouldn't it be tooth whitening? I find it hard to believe that whoever writes scripts for commercials would make such a glaring grammatical error, but then again, I'm wondering if they have. What do you say?"Richard is unequivocal in his response. "You’re right; they're wrong; case closed!"
Well, I asked, is there anything wrong with an antiques show? an admissions committee? A Steelers fan? A singles bar? A publications list? Would you really go for "datum bank", "purple person eater", or "arm race"? What is the plural of manservant?
"No," Richard answered. In fact, he had had a paragraph to account for many exceptions to the rule, probably, he said, due to lower frequency of use than something like toothbrush. Blame the editors.
Well, yes and no. I'm glad to see that Richard accepts exceptions, but frequency has nothing to do with it (and couln't you just argue that teeth whitening is low frequency and be done with it?) No, it's a lot more interesting than that. According to Steven Pinker's Words and Rules.
"A simple explanation, based loosely on Kiparsky (1982), might run as follows. Morphological composition of words takes place in several stages. First there is a lexicon of memorized roots, including, according to the word/rule theory, irregular forms. That lexicon supplies the input to rules of regular derivational morphology, which creates complex words (including compounds)out of simple words and morphemes, outputting a stem. Stems are then inputted to a third component, regular inflection, which modifies the word according to its role in the sentence. In simplified form, the architecture of morphology would look like this:
- Memorized Roots (including irregulars) -->
- Complex word formation -->
- Regular inflection
The word mice, stored as a root in the first component, is available as an input to the compounding process in the second component, where it is joined to infested to yield mice-infested. In contrast, rats is not stored as a memorized root in the first component; it is formed from rat by an inflectional rule in the third component, too late to be inputted to the compounding rule in the second. Hence we get rat-infested but not rats-infested. "This accounts for the roots with irregular plurals (e.g., purple people eater), but what about the regular plurals (e.g., a red rats eater)? Pinker argues that a phrase can be inserted as the first constituent. That is, you have a [red rats] eater rather than a red [rat] eater. He goes on to argue that the plural in expressions like antiques show, admissions committee, and publications list are one-word phrases, built in the first of the three components above. So, if we have this option, when do we choose to make use of it? When, according to Pinker, we want to emphasise the individuality of the publications, etc. You can read all about it, in the chapter, "of mice and men" in Pinker's book Words and Rules.
In the end, as Margaret Atwood writes, "I felt mice-feet of apprehension," when I read Richard Firsten's prohibition. I hate it when people lay down the law when they've just made it up. Why not allow TV copy writers their "teeth whitening"? Because it's wrong. The wordanistas have spoken.