When I took my first graduate-level phonetics course, my semester project (with a couple other students) was a study of voice onset time (VOT), a measure of the temporal difference between the release of an oral closure and the onset of vocal fold oscillations. VOT is a salient cue to voicing distinctions in pre-vocalic position. So, for example, if I say ‘two’, the oral closure formed for the [t] is released well before the voicing begins for the vowel, whereas if I say ‘due’, voicing begins almost immediately after, or sometimes even before, the oral closure is released. (The wikipedia article linked above has a nice figure showing the difference between ‘tie’ and ‘die’, as well as an informative schematic illustration of VOT differences.)
So, in this VOT term project, the other team members and I came up with a list words with voiced and voiceless initial stop consonants (e.g., [d] and [t]). Most of our words were just fine, in that the consonants of interest immediately preceded vowels in stressed syllables, which is to say that they were well-suited to the measurement of VOT. However, we made the rookie mistake of including ‘truck’ in our list. It turns out that [tr] sequence ends up being produced as a retroflex affricate, something akin to the ‘ch’ in ‘chuck’. You can still measure VOT (or a VOT-like temporal difference), but VOT isn’t the only thing distinguishing a [tr] sequence from, say, a pre-vocalic [d]. Seems fairly obvious now, but this kind of thing is, one might argue, the point of an introductory phonetics term project.
Okay, so fast forward, um, a decade or so. My four-year-old son Solomon has been very interested in Star Wars lately, but we’re not particularly interested in letting him watch the movies, so we’ve been getting these goofy ‘early reader’ books from the library. The ‘level 1′ books have insets every few pages with very oddly-chosen vocabulary words and accompanying pictures (my favorite of these so far is the approximately 1-inch-square inset that says ‘space’, with a little picture of space, set into a background that consists of a much larger, and so more effectively illustrative, picture of space).
We have one called Tatooine Adventures right now, and one of the insets has a picture of C-3PO with the caption ‘droid’. Solomon asked what it said, and I told him. He thought about it for a few seconds, and pointed out that it should have a ‘g’ or ‘j’. Which is to say that [dr] wasn’t [dr] to him. It was an affricate, and he had already mapped affricates, correctly, onto the graphemes ‘g’ and ‘j’.
[cross-posted at Language Module, where permalinks don't currently work]