Editing Morphophonology (section)

==Morphophonemes and morphophonological rules==
When [[morpheme]]s combine, they influence each other's sound structure (whether analyzed at a phonetic or [[phonemic]] level), resulting in different variant pronunciations for the same morpheme. Morphophonology attempts to analyze these processes. A language's morphophonological structure is generally described with a series of rules which, ideally, can predict every morphophonological [[Alternation (linguistics)|alternation]] that takes place in the language.

An example of a morphophonological alternation in English is provided by the [[plural]] morpheme, written as "-s" or "-es". Its pronunciation varies among {{IPA|[s]}}, {{IPA|[z]}}, and {{IPA|[ɪz]}}, as in ''cats'', ''dogs'', and ''horses'' respectively. A purely phonological analysis would most likely assign to these three endings the phonemic representations {{IPA|/s/}}, {{IPA|/z/}}, {{IPA|/ɪz/}}. On a morphophonological level, however, they may all be considered to be forms of the underlying object {{IPA|⫽z⫽}}, which is a '''morphophoneme''' realized as one of the phonemic forms {{IPA|{s, z, ɪz&rbrace;}}. The different forms it takes are dependent on the segment at the end of the morpheme to which it attaches: the dependencies are described by morphophonological rules. (The behaviour of the English past tense ending "-ed" is similar: it can be pronounced {{IPA|/t/}}, {{IPA|/d/}} or {{IPA|/ɪd/}}, as in ''hoped'', ''bobbed'' and ''added''.)

The plural suffix "-s" can also influence the form taken by the preceding morpheme, as in the case of the words ''leaf'' and ''knife'', which end with {{IPA|[f]}} in the singular/but have {{IPA|[v]}} in the plural (''leaves'', ''knives''). On a morphophonological level, the morphemes may be analyzed as ending in a morphophoneme {{IPA|⫽F⫽}}, which becomes [[voiced consonant|voiced]] when a voiced consonant (in this case the {{IPA|⫽z⫽}} of the plural ending) is attached to it. The rule may be written symbolically as {{IPA|/F/}} &rarr; [α<sub>voice</sub>] / {{IPA|__}} [α<sub>voice</sub>]. This expression is called Alpha Notation in which α can be + (positive value) or − (negative value).

Common conventions to indicate a morphophonemic rather than phonemic representation include double slashes (⫽&nbsp;&nbsp;⫽) (as above, implying that the transcription is 'more phonemic than simply phonemic'). This is the only convention consistent with the IPA. Other conventions include pipes (|&nbsp;&nbsp;|), double pipes (‖&nbsp;&nbsp;‖){{efn|The IPA provides single and double pipes for minor and major suprasegmental groups, and these are scarcely distinguishable from the letters for dental and alveolar-lateral [[Click consonant|clicks]].}} and braces ({&nbsp;&nbsp;}).{{efn|The IPA provides braces for prosodic notation.}} Braces, from a convention in [[set theory]], tend to be used when the phonemes are all listed, as in {{IPA|{s, z, ɪz&rbrace;}} and {{IPA|{t, d, ɪd&rbrace;}} for the English plural and past-tense morphemes {{IPA|⫽z⫽}} and {{IPA|⫽d⫽}} above.<ref>{{cite book|last1=Gibbon|first1=Dafydd|last2=Moore|first2=Roger|last3=Winski|first3=Richard|title=Handbook of Standards and Resources for Spoken Language Systems: Spoken language characterisation|date=1998|publisher=Walter de Gruyter|location=Berlin; New York|isbn=9783110157345|pages=61–62|url=https://books.google.com/books?id=8cxtWcsAk5MC&pg=PA61|language=en}}</ref>

For instance, the English word ''cats'' may be transcribed phonetically as {{IPA|[ˈkʰæʔts]}}, phonemically as {{IPA|/ˈkæts/}} and morphophonemically as {{IPA|⫽ˈkætz⫽}}, if the plural is argued to be underlyingly {{IPA|⫽z⫽}}, assimilating to {{IPA|/s/}} after a voiceless nonsibilant. The tilde ~ may indicate morphological alternation, as in {{IPA|⫽ˈniːl ~ nɛl+t⫽}} or {{IPA|{n iː~ɛ l}, {n iː~ɛ l+t&rbrace;}} for ''kneel~knelt'' (the plus sign '+' indicates a morpheme boundary).<ref>Collinge (2002) ''An Encyclopedia of Language'', §4.2.</ref>