In linguistic typology, tripartite alignment is a type of morphosyntactic alignment in which the main argument ('subject') of an intransitive verb, the agent argument ('subject') of a transitive verb, and the patient argument ('direct object') of a transitive verb are each treated distinctly in the grammatical system of a language. This is in contrast with nominative-accusative and ergative-absolutive alignment languages, in which the argument of an intransitive verb patterns with either the agent argument of the transitive (in accusative languages) or with the patient argument of the transitive (in ergative languages). Thus, whereas in English, "she" in "she runs" patterns with "she" in "she finds it", and an ergative language would pattern "she" in "she runs" with "her" in "he likes her", a tripartite language would treat the "she" in "she runs" as morphologically and/or syntactically distinct from either argument in "he likes her". Which languages constitute genuine examples of a tripartite case alignment is a matter of debate; however, Wangkumara, Nez Perce, Ainu, Vakh dialects of Khanty, Semelai, Kalaw Lagaw Ya, Kham, and Yazghulami have all been claimed to demonstrate tripartite structure in at least some part of their grammar. While tripartite alignments are rare in natural languages, they have proven popular in constructed languages, notably the Na'vi language featured in 2009's Avatar. In languages with morphological case, a tritransitive alignment typically marks the agent argument of a transitive verb with an ergative case, the patient argument of a transitive verb with the accusative case, and the argument of an intransitive verb with an intransitive case. Tripartite, Ergative and Accusative systems A tripartite language does not maintain any syntactic or morphological equivalence (such as word order or grammatical case) between the core argument of intransitive verbs and either core argument of transitive verbs. In full tripartite alignment systems, this entails the agent argument of intransitive verbs always being treated differently from each of the core arguments of transitive verbs, whereas for mixed system intransitive alignment systems this may only entail that certain classes of noun are treated differently between these syntactic positions. The arguments of a verb are usually symbolized as follows: A = 'agent' argument of a transitive verb (traditional transitive subject) O = 'patient' argument of a transitive verb (traditional transitive object) S = argument of an intransitive verb (traditional intransitive subject) The relationship between accusative, ergative, and tripartite alignments can be schematically represented as follows: See