Genetic relationship (linguistics)

In linguistics, genetic relationship is the usual term for the relationship which exists between languages that are members of the same language family. The term genealogical relationship is sometimes used to avoid confusion with the unrelated use of the term in biological genetics. Languages that possess genetic ties with one another belong to the same linguistic grouping, known as a language family. These ties are established through use of the comparative method of linguistic analysis.

Two languages are considered to be genetically related if one is descended from the other or if both are descended from a common ancestor. For example, Italian is descended from Latin. Italian and Latin are therefore said to be genetically related. Spanish is also descended from Latin. Therefore, Spanish and Italian are genetically related. In a similar way, Danish, Swedish and Norwegian are genetically related through the North Germanic branch of the Indo-European language family.

The classification of languages into language families begins by making a list of words in the potential languages that exhibit lexical and grammatical similarities; that is, they are similar in sound and meaning. The next step is to determine how the similarities originated. There are three possibilities: convergence, borrowing, and common origin. Convergence is the chance similarity of sound and meaning of a word in two different languages and "is based on the principle that a word is an arbitrary association of sound and meaning". An example of convergence is that many unrelated languages have words similar to mama and papa for 'mother' and 'father'. Borrowing results from the exchanging of words between languages in close contact with one another. Once convergence and borrowing have been eliminated as possible explanations for similarities in sound and meaning of words, the last explanation is common origin. It can be assumed that the similarities occurred due to descent from a common ancestor, and the words are known as cognates. The set of all cognates of a word is the etymology of the word.

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