patterns can never be completely separated from how they are produced and heard, and production and perception are always influenced by the overarching linguistic organization.
All human beings have basically the same structures in their vocal tracts and in their ears. So why are languages so different? To some extent, it is because they use different sounds from the repertoire of possible human vocal tract noises. Arabic uses pharyngeal and uvular fricatives, while English does not. French selects front round vowels (such as [y] and [ø]), English selects lax high vowels ([I] and [U]), and Spanish sticks to basic [i, e, a, o, u]. Thus, to some extent, learning to speak a new language is about learning to make new sounds.
But there’s more to it than that. Languages differ not only in the sounds they use, but in how they organize those sounds into patterns. Consider, for example, the voiced obstruents of English and Spanish.
Notice that [d] and [ð] have a different distribution in Spanish. There are no minimal pairs – no [ðama] contrasting with [dama], no [lado] contrast- ing with [laðo]. The difference between [d] and [ð] is not contrastive; the [d]
versus [ð] difference is never used in Spanish to signal a difference in meaning. Instead, the two sounds have different distributions: only [d] is found in initial position, and only [ð] is found between vowels. The distri- bution is predictable. If you know the context (the position in the word, or the surrounding sounds), you can predict whether [d] or [ð] will be used.
When the occurrence of two different sounds is predictable based on the context, we say that the two sounds are in complementary distribu- tion. (Not “complimentary” in the sense of “nice,” but “complementary” in the mathematical sense that one half of a circle is the complement of the other half.) The sounds [d] and [ð] are in complementary distribution in Spanish. (The situation is slightly more complicated when contexts other than word-initial and between vowels are considered, but the principle of complementary distribution holds. There is only [d] after [n], for instance, and only [ð] after [r].)
When two sounds in a language form minimal pairs (that is, if their dis- tribution is unpredictable and contrastive), those two sounds represent different phonemes. When two sounds in a language are in complemen- tary distribution (that is, their distribution is predictable and noncon- trastive), the two sounds are allophonesof the same phoneme. In English, [d] and [ð] represent different phonemes. In Spanish [d] and [D] are allo- phones of the same phoneme.
Another way to say this is that a phoneme is a label for a group of sounds that are perceived by the speaker to be the “same” sound, and the allophones are the different ways of pronouncing that sound depending upon the context in which it is produced. To the Spanish speaker, if he/she pays any conscious attention at all, [ð] is just “a way of saying d.” A speak- er of the language knows when the [d] allophone is called for and when the [ð] allophone is appropriate. If you’re learning Spanish as a second lan- guage, you may have been taught this distribution as a rule, something like “the sound [d] is pronounced as [ð] between vowels.” There is no such rule relating [d] and [ð] in English. They are separate phonemes.
We may diagram the situation as follows:
Phonemes are indicated by slashes, while allophones are indicated by brack- ets. At the allophonic level, English and Spanish have the same sounds. At the phonemic level, English has a contrast where Spanish has none.
Differences in phonemic and allophonic distribution pose significant problems for speakers of one language who are learning to speak another.
A native speaker of Spanish learning English will have trouble with the distinction between denand then. To him/her, [d] and [D] count as the same
sound, so he/she will tend to hear them that way, and to pronounce them according to the principles of his/her own language. A Spanish speaker may tend to say [dEn] for then(using the word-initial allophone), and [QDer]
for adder(using the intervocalic allophone). These are not random errors, but a result of imposing the phonological organization of the first lan- guage onto the words of the second.
The first thing a phonologist working to describe a previously unknown language wants to figure out is its inventory of sounds: what sounds does the language use? But the second thing he/she wants to figure out is which sound differences the language uses to encode differences between words: what are the phonemes? Next, a phonologist tries to figure out the different allophones of each phoneme by identifying predictable patterns of complementary distribution. Answering questions about contrast and predictability of sounds in a language is the main work of phonology.
Box 1.2 Another look at phonemes and allophones The example above shows a case where a distinction that is con- trastive in English is not contrastive in another language. The reverse occurs too, of course. Consider the case of voiceless stops in Thai and English.
A voiceless stop ([p], [t], or [k]) may be produced with or without an extra puff of air, called aspiration. In English, you can feel the aspira- tion if you hold your fingertips an inch or so in front of your lips as you say popor pill. But you won’t feel any aspiration for a [p] that occurs after [s] as in spotor spill. In English, stops produced with an extra puff of air are aspirated, those without the extra puff are unaspirated. Speakers of both Thai and English produce a full set of aspirated voiceless stops [ph, th, kh] and unaspirated voiceless stops [p, t, k]. Though the inventory of voiceless stops is the same, the languages use the inventory in different ways. Some Thai and English words using these sounds are shown below.
Thai: Aspirated: Unaspirated:
phàt ‘to stir fry’ pàt ‘to wipe’
thun ‘a fund’ tun ‘to hoard’
khâ:w ‘step’ kâ:w ‘rice’
English: Aspirated: Unaspirated:
phIl pill spIl spill
thIl till stil still
khil kill skIl skill
In Thai, aspiration is contrastive. The difference between [p] and [ph] makes a difference in meaning, and thus minimal pairs with aspirated and unaspirated stops (such as [phàt] and [pàt]) are easy to find. [p] and [ph] are two different phonemes, as are [t] and [th], and [k] and [kh].