Editing Grammatical case (section)

==Linguistic typology==

===Morphosyntactic alignment===
{{main|Morphosyntactic alignment}}

Languages are categorized into several case systems, based on their ''morphosyntactic alignment''—how they group verb [[agent (linguistics)|agents]] and [[patient (linguistics)|patients]] into cases:

* ''[[nominative–accusative language|Nominative–accusative]]'' (or simply ''accusative''): The argument (subject) of an intransitive verb is in the same case as the agent (subject) of a transitive verb; this case is then called the ''[[nominative case]]'', with the patient (direct object) of a transitive verb being in the ''[[accusative case]]''.
* ''[[ergative–absolutive language|Ergative–absolutive]]'' (or simply ''ergative''): The argument (subject) of an intransitive verb is in the same case as the patient (direct object) of a transitive verb; this case is then called the ''[[absolutive case]]'', with the agent (subject) of a transitive verb being in the ''[[ergative case]]''.
* ''[[ergative–accusative language|Ergative–accusative]]'' (or ''tripartite''): The argument (subject) of an intransitive verb is in its own case (the ''[[intransitive case]]''), separate from that of the agent (subject) or patient (direct object) of a transitive verb (which is in the ergative case or accusative case, respectively).
* ''[[active–stative language|Active–stative]]'' (or simply ''active''): The argument (subject) of an intransitive verb can be in one of two cases; if the argument is an ''agent'', as in "He ate", then it is in the same case as the agent (subject) of a transitive verb (sometimes called the ''agentive case''), and if it is a ''patient'', as in "He tripped", then it is in the same case as the patient (direct object) of a transitive verb (sometimes called the ''patientive case'').
* ''[[trigger language|Trigger]]'': One noun in a sentence is the topic or focus. This noun is in the [[trigger case]], and information elsewhere in the sentence (for example a [[verb]] [[affix]] in [[Tagalog language|Tagalog]]) specifies the role of the trigger. The trigger may be identified as the agent, patient, etc. Other nouns may be inflected for case, but the inflections are overloaded; for example, in Tagalog, the subject and object of a verb are both expressed in the [[genitive case]] when they are not in the trigger case.

The following are systems that some languages use to mark case instead of, or in addition to, declension:
* '''Positional''': Nouns are not inflected for case; the position of a noun in the sentence expresses its case.
* [[Adposition]]al: Nouns are accompanied by words that mark case.

===Language families===
*With a few exceptions, most languages in the [[Finno-Ugric languages|Finno-Ugric]] family make extensive use of cases. [[Finnish language|Finnish]] has 15 cases according to the traditional description (or up to 30 depending on the interpretation).<ref>{{cite web |url=http://users.jyu.fi/~pamakine/kieli/suomi/sijat/sijatadverbien.html |title=Finnish Grammar – Adverbial cases |publisher=Users.jyu.fi |access-date=15 September 2014 |archive-date=11 May 2019 |archive-url=https://web.archive.org/web/20190511205833/http://users.jyu.fi/~pamakine/kieli/suomi/sijat/sijatadverbien.html |url-status=live }}</ref> However, only 12 are commonly used in speech (see [[Finnish noun cases]] and [[Finnish locative system]]). [[Estonian language|Estonian]] has 14 (see [[Estonian locative system]]) and [[Hungarian language|Hungarian]] has 18, both with additional archaic cases used for some words.
*[[Turkic languages|Turkic]], [[Mongolic languages|Mongolic]], and [[Tungusic languages|Tungusic]] languages also exhibit complex case systems. Since the abovementioned languages, along with [[Korean language|Korean]] and [[Japanese language|Japanese]], shared certain similarities, linguists proposed an [[Altaic languages|Altaic]] family and reconstructed its case system; although the hypothesis had been largely discredited.
*The [[Tsez language]], a [[Northeast Caucasian languages|Northeast Caucasian language]], has 64 cases.
*The original version of John Quijada's [[constructed language]] [[Ithkuil]] has 81 noun cases,<ref>{{cite web |url=http://www.ithkuil.net/ithkuil-ch4-case.htm |title=A Philosophical Grammar of Ithkuil, a Constructed Language – Chapter 4: Case Morphology |publisher=Ithkuil.net |access-date=15 September 2014 |url-status=dead |archive-url=https://web.archive.org/web/20090608003723/http://www.ithkuil.net/ithkuil-ch4-case.htm |archive-date=June 8, 2009}}</ref> and its descendant [[Ilaksh]] and Ithkuil after the 2011 revision both have 96 noun cases.<ref>{{cite web |url=http://ithkuil.net/ilaksh/Chapter_4.html |title=Chapter 4 |access-date=15 September 2014 |url-status=dead |archive-url=https://web.archive.org/web/20090312010557/http://ithkuil.net/ilaksh/Chapter_4.html |archive-date=March 12, 2009}}</ref><ref>{{cite web |url=http://ithkuil.net/04_case.html |title=A Grammar of the Ithkuil Language – Chapter 4: Case Morphology |publisher=Ithkuil.net |access-date=15 September 2014 |archive-date=26 February 2015 |archive-url=https://web.archive.org/web/20150226082350/http://www.ithkuil.net/04_case.html |url-status=live }}</ref>

The [[lemma (morphology)|lemma]] form of words, which is the form chosen by convention as the canonical form of a word, is usually the most [[markedness|unmarked]] or basic case, which is typically the nominative, trigger, or absolutive case, whichever a language may have.