Editing Slavic languages (section)

===Length, accent, and tone===
An area of great difference among Slavic languages is that of [[prosody (linguistics)|prosody]] (i.e. syllabic distinctions such as [[vowel length]], [[accent (phonetics)|accent]], and [[tone (linguistics)|tone]]). Common Slavic had a complex system of prosody, inherited with little change from [[Proto-Indo-European language|Proto-Indo-European]]. This consisted of [[phonemic]] vowel length and a free, mobile [[pitch accent]]:
* All vowels could occur either short or long, and this was phonemic (it could not automatically be predicted from other properties of the word).
* There was (at most) a single accented syllable per word, distinguished by higher pitch (as in modern [[Japanese language|Japanese]]) rather than greater dynamic stress (as in English).
* Vowels in accented syllables could be pronounced with either a rising or falling tone (i.e. there was ''pitch accent''), and this was phonemic.
* The accent was ''free'' in that it could occur on any syllable and was phonemic.
* The accent was ''mobile'' in that its position could potentially vary among closely related words within a single paradigm (e.g. the accent might land on a different syllable between the nominative and genitive singular of a given word).
* Even within a given inflectional class (e.g. masculine ''i''-stem nouns), there were multiple accent patterns in which a given word could be inflected. For example, most nouns in a particular inflectional class could follow one of three possible patterns: Either there was a consistent accent on the root (pattern A), predominant accent on the ending (pattern B), or accent that moved between the root and ending (pattern C). In patterns B and C, the accent in different parts of the paradigm shifted not only in location but also type (rising vs. falling). Each inflectional class had its own version of patterns B and C, which might differ significantly from one inflectional class to another.

The modern languages vary greatly in the extent to which they preserve this system. On one extreme, Serbo-Croatian preserves the system nearly unchanged (even more so in the conservative [[Chakavian dialect]]); on the other, Macedonian has basically lost the system in its entirety. Between them are found numerous variations:
* Slovenian preserves most of the system but has shortened all unaccented syllables and lengthened non-final accented syllables so that vowel length and accent position largely co-occur.
* Russian and Bulgarian have eliminated distinctive vowel length and tone and converted the accent into a [[stress (linguistics)|stress accent]] (as in English) but preserved its position. As a result, the complexity of the mobile accent and the multiple accent patterns still exists (particularly in Russian because it has preserved the Common Slavic noun inflections, while Bulgarian has lost them).
* Czech and Slovak have preserved phonemic vowel length and converted the distinctive tone of accented syllables into length distinctions. The phonemic accent is otherwise lost, but the former accent patterns are echoed to some extent in corresponding patterns of vowel length/shortness in the root. Paradigms with mobile vowel length/shortness do exist but only in a limited fashion, usually only with the zero-ending forms (nom. sg., acc. sg., and/or gen. pl., depending on inflectional class) having a different length from the other forms. (Czech has a couple of other "mobile" patterns, but they are rare and can usually be substituted with one of the "normal" mobile patterns or a non-mobile pattern.)
* [[Old Polish]] had a system very much like Czech. Modern Polish has lost vowel length, but some former short-long pairs have become distinguished by quality (e.g. {{IPA link|[o oː]}} > {{IPA|[o u]}}), with the result that some words have vowel-quality changes that exactly mirror the mobile-length patterns in Czech and Slovak.