In linguistics, syncretism exists when functionally distinct occurrences of a single lexeme, morph or phone are identical in form. The term arose in historical linguistics, referring to the convergence of morphological forms within inflectional paradigms. In such cases, a former distinction has been 'syncretized'. However, syncretism is also used to describe any situation where multiple syntactical features share the same inflectional marker, without implying a distinction ever existed. The term syncretism is often used when a fairly regular pattern can be observed across a paradigm.
Syncretism is a specific form of linguistic homophony. Homophony refers to any instance of two words or morphemes with the same pronunciation (form) but different meaning. Syncretism is a type of homophony that occurs within a specific paradigm in which the syntax would require separate forms. Accidental homophony does occur in paradigms, however, and linguist Sebastian Bank of the University of Leipzig makes the distinction between accidental homophony and syncretism in paradigms through natural classes. When a set of identical paradigmatic forms are connected by a feature in common, and a native speaker cannot tell the difference between the forms, this is said to be syncretism.
Syncretism can arise through either phonological or morphological change. Baerman et al. call these two sources of syncretism "blind phonological change" and "morphosyntactic readjustment". In the case of phonological change, originally distinct forms change to be pronounced identically, so that their distinctness is lost. Such change can often be observed in the modern German verb paradigm: the infinitive 'to take' comes from Old High German , the first person plural declension comes from , and the third person plural comes from . This is also an example of syncretism manifested in lexemes.
Some scholars, according to Baerman et al., purport that blind phonological change should only be considered to yield homophony, not syncretism. This distinction between the two sources of syncretism is important in theory, but is harder to maintain de facto.
In the case of morphological change, one form stops being used and is replaced by the other. This change can be exemplified by the syncretism in Latin's third-declension nouns, whose nouns take the same form in nominative and vocative cases.
Forms of syncretism
Baerman et al. identify three forms of syncretism. These are simple syncretism, nested syncretism, and contrary syncretism. Simple syncretism occurs when a minimum of two cells in a paradigm are syncretic. Nested syncretism occurs when more than two cells in a paradigm are syncretic to the same form. Contrary syncretism occurs when there are multiple cases of simple syncretism, in which each case in the paradigm of the simple syncretism is separate from the others.
In the chart above a model of simple syncretism is shown in the singular and plural forms of the second person subject pronoun in English. There is another example in the chart of simple syncretism in the masculine and feminine third person plural subject pronouns, both realized as they. Together these two cases of syncretism are an example of contrary syncretism.
The chart below shows a model of nested syncretism, in which more than one cell in the paradigm of subjunctive verb conjugation in Brazilian Portuguese is realized as the same form, "seja."
Stump, in his 2001 book Inflectional Morphology: A Theory of Paradigm Structure, identifies four distinct types of syncretism. This model is called directional syncretism, as it refers to the direction in which the syncretism occurs and progresses. The four directions of syncretism are unidirectional, bidirectional, unstipulated, and symmetrical.
Unidirectional syncretism is the concept that the form of one cell in the paradigm is mapped onto another cell. This is exemplified through the exploration of accusative forms of neutral words in Indo-European languages. In Indo-European languages that have the neutral gender, the nominative and accusative forms of neuter words tend to be the same. The accusative case is the marked case (meaning the presence of accusative implies the presence of nominative, while the nominative case can exist in a language without the accusative), and so it can be assumed that the form of the nominative neuter word was mapped onto the accusative form. As in the Slovak word for "word", slovo, which is the same in both nominative and accusative, while masculine animate and feminine words change from case to case, as shown in the chart below.