This glossary gives a general overview of the various sound laws that have been formulated by linguists for the various Indo-European languages. A concise description is given for each rule; more details are given in their respective articles.
The Indo-European languages are a language family native to the northern Indian subcontinent, the overwhelming majority of Europe, and the Iranian plateau. Some European languages of this family—English, French, Portuguese, Russian, Dutch, and Spanish—have expanded through colonialism in the modern period and are now spoken across several continents. The Indo-European family is divided into several branches or sub-families, of which there are eight groups with languages still alive today: Albanian, Armenian, Balto-Slavic, Celtic, Germanic, Hellenic, Indo-Iranian, and Italic; another nine subdivisions are now extinct.
In linguistics, the Indo-European ablaut is a system of apophony in the Proto-Indo-European language (PIE).
The laryngeal theory is a theory in historical linguistics positing that the Proto-Indo-European (PIE) language included a number of laryngeal consonants that are not reconstructable by direct application of the comparative method to the Indo-European family. The "missing" sounds remain consonants of an indeterminate place of articulation towards the back of the mouth, though further information is difficult to derive. Proponents aim to use the theory to:
Grassmann's law, named after its discoverer Hermann Grassmann, is a dissimilatory phonological process in Ancient Greek and Sanskrit which states that if an aspirated consonant is followed by another aspirated consonant in the next syllable, the first one loses the aspiration. The descriptive version was given for Sanskrit by Pāṇini.
A yer is either of two letters in Cyrillic alphabets, ъ and ь. The Glagolitic alphabet used, as respective counterparts, the letters (Ⱏ) and (Ⱐ). They originally represented phonemically the "ultra-short" vowels in Slavic languages, including Old Church Slavonic, and are collectively known as the yers.
The Balto-Slavic languages form a branch of the Indo-European family of languages, traditionally comprising the Baltic and Slavic languages. Baltic and Slavic languages share several linguistic traits not found in any other Indo-European branch, which points to a period of common development and origin.
The history of the Slavic languages stretches over 3000 years, from the point at which the ancestral Proto-Balto-Slavic language broke up into the modern-day Slavic languages which are today natively spoken in Eastern, Central and Southeastern Europe as well as parts of North Asia and Central Asia.
The glottalic theory is that Proto-Indo-European had ejective or otherwise non-pulmonic stops, *pʼ *tʼ *kʼ, instead of the plain voiced ones, *b *d *ɡ as hypothesized by the usual Proto-Indo-European phonological reconstructions.
Proto-Balto-Slavic is a reconstructed hypothetical proto-language descending from Proto-Indo-European (PIE). From Proto-Balto-Slavic, the later Balto-Slavic languages are thought to have developed, composed of the Baltic and Slavic sub-branches, and including modern Lithuanian, Polish, Russian and Serbo-Croatian, among others.
The Proto-Greek language is the Indo-European language which was the last common ancestor of all varieties of Greek, including Mycenaean Greek, the subsequent ancient Greek dialects and, ultimately, Koine, Byzantine and Modern Greek. Proto-Greek speakers entered Greece sometime between 2200 and 1900 BC, with the diversification into a southern and a northern group beginning by approximately 1700 BC.
Proto-Celtic, or Common Celtic, is the hypothetical ancestral proto-language of all known Celtic languages, and a descendant of Proto-Indo-European. It is not attested in writing but has been partly reconstructed through the comparative method. Proto-Celtic is generally thought to have been spoken between 1300 and 800 BC, after which it began to split into different languages. Proto-Celtic is often associated with the Urnfield culture and particularly with the Hallstatt culture. Celtic languages share common features with Italic languages that are not found in other branches of Indo-European, suggesting the possibility of an earlier Italo-Celtic linguistic unity.
Proto-Baltic is the unattested, reconstructed ancestral proto-language of all Baltic languages. It is not attested in writing, but has been partly reconstructed through the comparative method by gathering the collected data on attested Baltic and other Indo-European languages. It represents the common Baltic speech that approximately was spoken between the 3rd millennium BC and ca. 5th century BC, after which it began dividing into West and East Baltic languages. Proto-Baltic is thought to have been a fusional language and is associated with the Corded Ware and Trzciniec cultures.
As the Proto-Indo-European language (PIE) broke up, its sound system diverged as well, as evidenced in various sound laws associated with the daughter Indo-European languages. Especially notable is the palatalization that produced the satem languages, along with the associated ruki sound law. Other notable changes include:
The phonology of the Proto-Indo-European language (PIE) has been reconstructed by linguists, based on the similarities and differences among current and extinct Indo-European languages. Because PIE was not written, linguists must rely on the evidence of its earliest attested descendants, such as Hittite, Sanskrit, Ancient Greek, and Latin, to reconstruct its phonology.
Winter's law, named after Werner Winter, who postulated it in 1978, is a proposed sound law operating on Balto-Slavic short vowels */e/, */o/, */a/, */i/ and */u/ according to which they lengthen before unaspirated voiced stops, and that syllable gains a rising, acute accent.
Hirt's law or Hirt–Illich-Svitych's law, named after Hermann Hirt, who originally postulated it in 1895, is a Balto-Slavic sound law that triggered the retraction of the accent under certain conditions.
Osthoff's law is an Indo-European sound law which states that long vowels shorten when followed by a resonant, followed in turn by another consonant. It is named after German Indo-Europeanist Hermann Osthoff, who first formulated it.
Languages of the Indo-European family are classified as either centum languages or satem languages according to how the dorsal consonants of the reconstructed Proto-Indo-European language (PIE) developed. An example of the different developments is provided by the words for "hundred" found in the early attested Indo-European languages. In centum languages, they typically began with a sound, but in satem languages, they often began with.
Proto-Slavic is the unattested, reconstructed proto-language of all Slavic languages. It represents Slavic speech approximately from the 2nd millennium BC through the 6th century AD. As with most other proto-languages, no attested writings have been found; scholars have reconstructed the language by applying the comparative method to all the attested Slavic languages and by taking into account other Indo-European languages.
The Proto-Slavic language, the hypothetical ancestor of the modern-day Slavic languages, developed from the ancestral Proto-Balto-Slavic language, which is the parent language of the Balto-Slavic languages. The first 2,000 years or so consist of the pre-Slavic era, a long period during which none of the later dialectal differences between Slavic languages had yet emerged. The last stage in which the language remained without internal differences that later characterize different Slavic languages can be dated around AD 500 and is sometimes termed Proto-Slavic proper or Early Common Slavic. Following this is the Common Slavic period, during which the first dialectal differences appeared but the entire Slavic-speaking area continued to function as a single language, with sound changes tending to spread throughout the entire area. By around 1000, the area had broken up into separate East Slavic, West Slavic and South Slavic languages, and in the following centuries it broke up further into the various modern Slavic languages of which the following are extant: Belarusian, Russian, Rusyn and Ukrainian in the East; Czech, Slovak, Polish, Kashubian and the Sorbian languages in the West, and Bulgarian, Macedonian, Serbo-Croatian and Slovenian in the South.