In
linguistics
Linguistics is the scientific study of human language. It is called a scientific study because it entails a comprehensive, systematic, objective, and precise analysis of all aspects of language, particularly its nature and structure. Linguis ...
, the comparative method is a technique for studying the development of languages by performing a feature-by-feature comparison of two or more languages with
common descent
Common descent is a concept in evolutionary biology applicable when one species is the ancestor of two or more species later in time. All living beings are in fact descendants of a unique ancestor commonly referred to as the last universal comm ...
from a shared ancestor and then extrapolating backwards to infer the properties of that ancestor. The comparative method may be contrasted with the method of
internal reconstruction
Internal reconstruction is a method of reconstructing an earlier state in a language's history using only language-internal evidence of the language in question.
The comparative method compares variations between languages, such as in sets of c ...
in which the internal development of a single language is inferred by the analysis of features within that language. Ordinarily, both methods are used together to reconstruct prehistoric phases of languages; to fill in gaps in the historical record of a language; to discover the development of phonological, morphological and other linguistic systems and to confirm or to refute hypothesised relationships between languages.
The comparative method was developed over the 19th century. Key contributions were made by the Danish scholars
Rasmus Rask
Rasmus Kristian Rask (; born Rasmus Christian Nielsen Rasch; 22 November 1787 – 14 November 1832) was a Danish linguist and philologist. He wrote several grammars and worked on comparative phonology and morphology. Rask traveled extensively to ...
and
Karl Verner
Karl Adolph Verner (; 7 March 1846 – 5 November 1896) was a Danish linguist. He is remembered today for Verner's law, which he published in 1876.
Biography
Verner's interest in languages was stimulated by reading about the work of Rasmus Chris ...
and the German scholar
Jacob Grimm
Jacob Ludwig Karl Grimm (4 January 1785 – 20 September 1863), also known as Ludwig Karl, was a German author, linguist, philologist, jurist, and folklorist. He is known as the discoverer of Grimm's law of linguistics, the co-author of th ...
. The first linguist to offer reconstructed forms from a
proto-language
In the tree model of historical linguistics, a proto-language is a postulated ancestral language from which a number of attested languages are believed to have descended by evolution, forming a language family. Proto-languages are usually unattest ...
was
August Schleicher
August Schleicher (; 19 February 1821 – 6 December 1868) was a German linguist. His great work was ''A Compendium of the Comparative Grammar of the Indo-European Languages'' in which he attempted to reconstruct the Proto-Indo-European languag ...
, in his ''Compendium der vergleichenden Grammatik der indogermanischen Sprachen'', originally published in 1861. Here is Schleicher's explanation of why he offered reconstructed forms:
In the present work an attempt is made to set forth the inferred Indo-European original language side by side with its really existent derived languages. Besides the advantages offered by such a plan, in setting immediately before the eyes of the student the final results of the investigation in a more concrete form, and thereby rendering easier his insight into the nature of particular Indo-European languages
The Indo-European languages are a language family native to the overwhelming majority of Europe, the Iranian plateau, and the northern Indian subcontinent. Some European languages of this family, English, French, Portuguese, Russian, Dutc ...
, there is, I think, another of no less importance gained by it, namely that it shows the baselessness of the assumption that the non-Indian Indo-European languages were derived from Old-Indian (Sanskrit
Sanskrit (; attributively , ; nominally , , ) is a classical language belonging to the Indo-Aryan branch of the Indo-European languages. It arose in South Asia after its predecessor languages had diffused there from the northwest in the late ...
).
Definition
Principles
The aim of the comparative method is to highlight and interpret systematic
phonological
Phonology is the branch of linguistics that studies how languages or dialects systematically organize their sounds or, for sign languages, their constituent parts of signs. The term can also refer specifically to the sound or sign system of a ...
and
semantic
Semantics (from grc, σημαντικός ''sēmantikós'', "significant") is the study of reference, meaning, or truth. The term can be used to refer to subfields of several distinct disciplines, including philosophy, linguistics and comput ...
correspondences between two or more
attested language
In linguistics, attested languages are languages (living or dead) that have been documented and for which the evidence (attestation) has survived to the present day. Evidence may be recordings, transcriptions, literature or inscriptions. In cont ...
s. If those correspondences cannot be rationally explained as the result of
language contact
Language contact occurs when speakers of two or more languages or varieties interact and influence each other. The study of language contact is called contact linguistics. When speakers of different languages interact closely, it is typical for th ...
(
borrowings,
areal influence, etc.) or
linguistic universal
A linguistic universal is a pattern that occurs systematically across natural languages, potentially true for all of them. For example, ''All languages have nouns and verbs'', or ''If a language is spoken, it has consonants and vowels.'' Research i ...
s, and if they are sufficiently numerous, regular, and systematic that they cannot be dismissed as chance similarities, then it must be assumed that they descend from a single parent language called the '
proto-language
In the tree model of historical linguistics, a proto-language is a postulated ancestral language from which a number of attested languages are believed to have descended by evolution, forming a language family. Proto-languages are usually unattest ...
'.
A sequence of regular
sound change
A sound change, in historical linguistics, is a change in the pronunciation of a language. A sound change can involve the replacement of one speech sound (or, more generally, one phonetic feature value) by a different one (called phonetic chang ...
s (along with their underlying sound laws) can then be postulated to explain the correspondences between the attested forms, which eventually allows for the
reconstruction
Reconstruction may refer to:
Politics, history, and sociology
*Reconstruction (law), the transfer of a company's (or several companies') business to a new company
*'' Perestroika'' (Russian for "reconstruction"), a late 20th century Soviet Unio ...
of a proto-language by the methodical comparison of "linguistic facts" within a generalized system of correspondences.
Relation is considered to be "established beyond a reasonable doubt" if a reconstruction of the common ancestor is feasible.
In some cases, this reconstruction can only be partial, generally because the compared languages are too scarcely attested, the temporal distance between them and their proto-language is too deep, or their internal evolution render many of the sound laws obscure to researchers. In such case, a relation is considered plausible, but uncertain.
Terminology
''Descent'' is defined as transmission across the generations: children learn a language from the parents' generation and, after being influenced by their peers, transmit it to the next generation, and so on. For example, a continuous chain of speakers across the centuries links
Vulgar Latin
Vulgar Latin, also known as Popular or Colloquial Latin, is the range of non-formal Register (sociolinguistics), registers of Latin spoken from the Crisis of the Roman Republic, Late Roman Republic onward. Through time, Vulgar Latin would evolve ...
to all of its modern descendants.
Two languages are ''
genetically
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar working i ...
related'' if they descended from the same
ancestor language. For example,
Italian
Italian(s) may refer to:
* Anything of, from, or related to the people of Italy over the centuries
** Italians, an ethnic group or simply a citizen of the Italian Republic or Italian Kingdom
** Italian language, a Romance language
*** Regional Ita ...
and
French both come from
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
and therefore belong to the same family, the
Romance languages
The Romance languages, sometimes referred to as Latin languages or Neo-Latin languages, are the various modern languages that evolved from Vulgar Latin. They are the only extant subgroup of the Italic languages in the Indo-European language fam ...
. Having a large component of vocabulary from a certain origin is not sufficient to establish relatedness; for example, heavy
borrowing from
Arabic
Arabic (, ' ; , ' or ) is a Semitic languages, Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C ...
into
Persian
Persian may refer to:
* People and things from Iran, historically called ''Persia'' in the English language
** Persians, the majority ethnic group in Iran, not to be conflated with the Iranic peoples
** Persian language, an Iranian language of the ...
has caused more of the
vocabulary
A vocabulary is a set of familiar words within a person's language. A vocabulary, usually developed with age, serves as a useful and fundamental tool for communication and acquiring knowledge. Acquiring an extensive vocabulary is one of the la ...
of Modern Persian to be from Arabic than from the direct ancestor of Persian,
Proto-Indo-Iranian, but Persian remains a member of the Indo-Iranian family and is not considered "related" to Arabic.
However, it is possible for languages to have different degrees of relatedness.
English
English usually refers to:
* English language
* English people
English may also refer to:
Peoples, culture, and language
* ''English'', an adjective for something of, from, or related to England
** English national ide ...
, for example, is related to both
German
German(s) may refer to:
* Germany (of or related to)
** Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ge ...
and
Russian
Russian(s) refers to anything related to Russia, including:
*Russians (, ''russkiye''), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries
*Rossiyane (), Russian language term for all citizens and peo ...
but is more closely related to the former than to the latter. Although all three languages share a common ancestor,
Proto-Indo-European
Proto-Indo-European (PIE) is the reconstructed common ancestor of the Indo-European language family. Its proposed features have been derived by linguistic reconstruction from documented Indo-European languages. No direct record of Proto-Indo-E ...
, English and German also share a more recent common ancestor,
Proto-Germanic
Proto-Germanic (abbreviated PGmc; also called Common Germanic) is the reconstructed proto-language of the Germanic branch of the Indo-European languages.
Proto-Germanic eventually developed from pre-Proto-Germanic into three Germanic branc ...
, but Russian does not. Therefore, English and German are considered to belong to a subgroup of Indo-European that Russian does not belong to, the
Germanic languages
The Germanic languages are a branch of the Indo-European language family spoken natively by a population of about 515 million people mainly in Europe, North America, Oceania and Southern Africa. The most widely spoken Germanic language, Engli ...
.
The division of related languages into subgroups is accomplished by finding ''shared linguistic innovations'' that differentiate them from the parent language. For instance, English and German both exhibit the effects of a collection of sound changes known as
Grimm's Law
Grimm's law (also known as the First Germanic Sound Shift) is a set of sound laws describing the Proto-Indo-European (PIE) stop consonants as they developed in Proto-Germanic in the 1st millennium BC. First systematically put forward by Jacob Gr ...
, which Russian was not affected by. The fact that English and German share this innovation is seen as evidence of English and German's more recent common ancestor—since the innovation actually took place within that common ancestor, before English and German diverged into separate langua