morphosyntactic alignment for a more technical explanation. The term 'subject' has been found to be problematic when applied to languages which have any morphosyntactic alignment other than nominative-accusative, and hence, reference to the 'agent' argument of transitive sentences is preferred to the term 'subject'. Types of tripartite systems Languages may be designated as tripartite languages in virtue of having either a full tripartite morphosyntactic alignment, or in virtue of having a mixed system which results in tripartite treatment of one or more specific classes of nouns. Full tripartite systems A full tripartite system distinguishes between S, A and O arguments in all classes of nominals. It has been claimed that Wangkumara has the only recorded full tripartite alignment system. Example Wangkumara consistently differentiates marking on S, A, and O arguments in the morphology, as demonstrated in example (1) below: In the above example, the intransitive case in (a) is glossed NOM, in accordance with Breen's original transcription. Across (1), we see differential case suffixes for each of intransitive (NOM), ergative (ERG), and accusative (ACC) case. The same tripartite distinction is clear in the pronominal system: In the above examples, we see the first person singular pronoun taking different forms for each of the S, A, and O arguments (marked NOM, ERG and ABS respectively), indicating the tripartite alignment in pronominal morphology. Syntactic surveys of Wangkumara suggest this is generally true of the language as a whole. Hence, Wangkumara represents a case of a full tripartite alignment. Mixed systems More common than full tripartite systems, mixed system tripartite alignments either demonstrate tripartite alignment in some subsection of the grammar, or else lacks the ergative, the accusative, or both in some classes of nominals. An example of the former kind of mixed system may be Yazghulami, which exhibits tripartite alignment but only in the past tense. An example of the latter would be Nez Perce, which lacks ergative marking in the first and second person. The following examples from Nez Perce illustrate the intransitive-ergative-accusative opposition that holds in the third person: In the above examples, (2a) demonstrates the intransitive case marking (here coded as NOM), while (2b) demonstrates differential ergative and accusative markings. Thus, Nez Perce demonstrates tripartite differentiations in its third person morphology. Realizations of tripartite alignment Morphological tripartite alignment Syntactic tripartite alignment Passive and anti-passive constructions Ainu also shows the passive voice formation typical of nominative-accusative languages and the antipassive