Switch-reference

In linguistics, switch-reference (SR) describes any clause-level morpheme that signals whether certain prominent arguments in 'adjacent' clauses corefer. In most cases, it marks whether the subject of the verb in one clause is coreferent with that of the previous clause, or of a subordinate clause to the matrix (main) clause that is dominating it.

The basic distinction made by a switch-reference system is whether the following clause has the same subject (SS) or a different subject (DS). That is known as canonical switch-reference. For purposes of switch-reference, subject is defined as it is for languages with a nominative–accusative alignment: a subject is the sole argument of an intransitive clause or the agent of a transitive one. It holds even in languages with a high degree of ergativity.

The Washo language of California and Nevada exhibits a switch-reference system. When the subject of one verb is the same as the subject of the following verb, the verb takes no switch-reference marker. However, if the subject of one verb differs from the subject of the following verb, the verb takes the "different subject" marker, -š (examples from Mithun 1999:269):

The Seri language of northwestern Mexico also has a switch-reference system which is similar in most ways to those of other languages except for one very salient fact: the relevant argument in a passive clause is not the superficial subject of the passive verb but rather the always unexpressed underlying subject. In clauses with subject raising, it is the raised subject that is relevant.

The nominative subject is not always marked by switch-reference. For instance, many clauses, including those with impersonal or weather verbs, have no subject at all but can both bear and trigger switch-reference.

In addition, many languages exhibit non-canonical switch-reference, the co-referents of arguments other than the subject being marked by switch-reference. Here is an example from Kiowa (Watkins 1993):

Switch-reference markers often carry additional meanings or are at least fused with connectives that carry them. For instance, an switch-reference marker might mark a different subject and sequential events.

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