Phonotactics

Phonotactics (in Greek "phone" = voice and "tactic" = course) is a branch of phonology that deals with restrictions in a language on the permissible combinations of phonemes. Phonotactics defines permissible syllable structure, consonant clusters, and vowel sequences by means of "phonotactical constraints".

Phonotactic constraints are language specific. For example, in Japanese, consonant clusters like IPA|/st/ are not allowed, although they are in English. Similarly, the sounds IPA|/kn/ and IPA|/ɡn/ are not permitted at the beginning of a word in Modern English but are in German and Dutch.

Syllables have the following internal segmental structure:
*Onset (optional)
*Rime (obligatory, comprises Nucleus and Coda):
**Nucleus (obligatory)
**Coda (optional)

Both onset and coda may be empty, forming a vowel-only syllable, or alternatively, the nucleus can be occupied by a syllabic consonant.

English phonotactics

The English syllable (and word) "twelfths" IPA|/twɛlfθs/ is divided into the onset IPA|/tw/, the nucleus IPA|/ɛ/, and the coda IPA|/lfθs/, and it can thus be described as CCVCCCC (C = consonant, V = vowel). On this basis it is possible to form rules for which representations of phoneme classes may fill the cluster. For instance, English allows at most three consonants in an onset, but among native words under standard accents, phonemes in a three-consonantal onset are limited to the following scheme: [cite book
last = Crystal
first = David
authorlink = David Crystal
title = The Cambridge Encyclopedia of the English Language
publisher = Cambridge University Press
year = 2003
isbn = 9780521530330
pages = 243
chapter = 17: The Sound System ]

:IPA|/s/ + pulmonic + approximant::*IPA|/s/ + IPA|/m/ + IPA|/j/:*IPA|/s/ + IPA|/t/ + IPA|/j ɹ/:*IPA|/s/ + IPA|/p/ + IPA|/j ɹ l/:*IPA|/s/ + IPA|/k/ + IPA|/j ɹ l w/

This constraint can be observed in the pronunciation of the word "blue": originally, the vowel of "blue" was identical to the vowel of "cue", approximately IPA| [iw] . In most dialects of English, IPA| [iw] shifted to IPA| [juː] . Theoretically, this would produce **IPA| [bljuː] . The cluster IPA| [blj] , however, infringes the constraint for three-consonantal onsets in English. Therefore, the pronunciation has been reduced to IPA| [bluː] by elision of the IPA| [j] .

Other languages don't share the same constraint: compare Spanish "pliegue" IPA| [ˈpljeɣe] or French "pluie" IPA| [plɥi] .

onority hierarchy

In general, the rules of phonotactics operate around the sonority hierarchy, stipulating that the nucleus has maximal sonority and that sonority decreases as you move away from the nucleus. The voiceless alveolar fricative IPA| [s] is lower on the sonority hierarchy than the alveolar lateral approximant IPA| [l] , so the combination IPA|/sl/ is permitted in onsets and IPA|/ls/ is permitted in codas, but IPA|/ls/ is not allowed in onsets and IPA|/sl/ is not allowed in codas. Hence "slips" IPA|/slɪps/ and "pulse" IPA|/pʌls/ are possible English words while "*lsips" and "*pusl" are not. There are of course exceptions to this rule, but in general it holds for the phonotactics of most languagesFact|date=April 2008.

Notes and references