"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 from a shared ancestor and then extrapolating backwards to infer the properties of that ancestor."
The comparative method is a technique used to reconstruct the grammar and vocabulary of an ancestral language by comparing data from the descendant languages and identifying regular sound correspondences.
Language Families and Taxonomy: Understanding the relationships between different languages and grouping them into families based on their genetic and structural similarities.
Sound Changes: The study of how sounds evolve and change over time in different languages. These changes include phonetic changes, phonemic mergers, shifts in stress patterns, and various others.
Reconstruction Techniques: The process of inferring the linguistic features of an extinct language by analyzing available evidence, such as written texts or similar languages.
Proto-Language Reconstruction: When reconstructing a language family, starting with the earliest known ancestor of the whole family.
Comparative Grammar: The comparison of the grammatical structures of different languages, which may reveal similarities or differences between them.
Cognates and Borrowing: Identifying the sources of linguistic similarities and differences between different languages.
Divergence and Convergence: The divergence of languages due to natural human language variation and the convergence of languages due to contact and interaction.
Diachronic Typology: The study of language change over time and how it affects language typology, which is the classification of languages based on their structural features.
Mass Comparison: A controversial method of language comparison that involves comparing many languages at once instead of just two.
Phylogenetic Analysis: The use of computational methods to construct a family tree of a group of languages based on their linguistic features.
Lexicostatistics: A quantitative method of comparing languages based on the percentage of shared basic vocabulary.
Glottochronology: A method of estimating the time depth of linguistic relationships based on the frequency of lexical change over time.
Wave Theory: The idea that language change happens in waves of innovation and diffusion across different regions and populations.
Contact Linguistics: The study of the influence that one language has on another due to contact, including language borrowing, code-switching, and pidginization.
Socio-historical Linguistics: The interaction between language and society over time, including the role of language in cultural preservation and cultural change.
Internal reconstruction: This is a method of reconstructing the vocabulary and grammar of an unattested ancestor language by comparing the features of its descendant languages.
External reconstruction: This is a method of reconstructing the vocabulary and grammar of an unattested ancestor language by comparing it to known and recorded languages that are known to be unrelated.
Comparative reconstruction: This is a method of reconstructing the vocabulary and grammar of an unattested ancestor language by comparing the known features of its descendant languages to identify shared cognates and reconstruct their original forms.
Morphological reconstruction: This is a method that focuses on the reconstruction of the morphology of an unattested ancestor language, including noun and verb inflectional patterns.
Semantic reconstruction: This is a method that focuses on the reconstruction of the meanings of words in an unattested ancestor language by comparing the meanings of related words in descendant languages.
Phonological reconstruction: This is a method that focuses on the reconstruction of the sound system of an unattested ancestor language by comparing the phonemes and phonological rules of related languages.
Comparative-historical linguistics: This is a broader approach that combines several of the above methods and applies them to study the evolution of languages and language families over time.
Etymology: This is the study of the origins of words, their semantic evolution and their relationships with other words in the same language or across languages.
"The comparative method may be contrasted with the method of internal reconstruction 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 hypothesized relationships between languages."
"The comparative method emerged in the early 19th century with the birth of Indo-European studies, then took a definite scientific approach with the works of the Neogrammarians in the late 19th–early 20th century."
"Key contributions were made by the Danish scholars Rasmus Rask (1787–1832) and Karl Verner (1846–1896), and the German scholar Jacob Grimm (1785–1863)."
"The first linguist to offer reconstructed forms from a proto-language was August Schleicher (1821–1868) 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..."
"...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)."
"The comparative method... took a definite scientific approach with the works of the Neogrammarians in the late 19th–early 20th century."