Grammatical case
A grammatical case is a category of nouns and noun modifiers (determiners, adjectives, participles, and numerals), which corresponds to one or more potential grammatical functions for a nominal group in a wording. In various languages, nominal groups consisting of a noun and its modifiers belong to one of a few such categories. For instance, in English, one says "I see them" and "they see me": the nominative pronouns "I"/"they" represent the perceiver and the accusative pronouns "me"/"them" represent the phenomenon perceived. Here, nominative and accusative are cases, that is, categories of pronouns corresponding to the functions they have  in representation. English has largely lost its inflected case system but personal pronouns still have three cases, which are simplified forms of the nominative, accusative and genitive cases. They are used with personal pronouns: subjective case (I, you, he, she, it, we, they, who, whoever), objective case (me, you, him, her, it, us, them, whom, whomever) and possessive case (my, mine; your, yours; his; her, hers; its; our, ours; their, theirs; whose; whosever). Forms such as "I", "he" and "we" are used for the subject ("I kicked the ball"), and forms such as "me", "him" and "us" are used for  the object ("John kicked me"). As a language evolves, cases can merge (for instance, in Ancient Greek, the locative case merged with the dative case), a phenomenon formally called syncretism. Languages such as Ancient Greek, Armenian, Assamese, most Balto-Slavic languages, Basque, Bengali, most Caucasian languages including Georgian, most Dravidian languages, German, Icelandic, Japanese, Korean, Kurdish, Latin, Sanskrit, Tibetan, the Turkic languages and the Uralic languages have extensive case systems, with nouns, pronouns, adjectives, and determiners all inflecting (usually by means of different suffixes) to indicate their case. The number of cases differs between languages: Persian has two; modern English  has three but for pronouns only; Torlakian dialects, Classical and Modern Standard Arabic have three; German, Icelandic, Modern Greek, and Irish have four; Romanian and Ancient Greek have five; Bengali, Latin, Russian, Slovak, Slovenian, and Turkish each have at least six; Armenian, Czech, Georgian, Kajkavian, Latvian, Lithuanian, Polish, Serbo-Croatian and Ukrainian have seven; Mongolian, Sanskrit and Tamil have eight; Assamese has 10; Basque has 13; Estonian has 14; Finnish has 15; Hungarian has 18 and Tsez has 64 cases. Commonly encountered cases include nominative, accusative, dative and genitive. A role that one of those languages marks by case is  often marked in English with a preposition. For example, the English prepositional phrase "with (his) foot" (as in "John kicked the ball with his foot") might be rendered in Russian using a single noun in the instrumental case, or in Ancient Greek as (, meaning "the foot") with both words (the definite article, and the noun () "foot") changing to dative form. More formally, case has been defined as "a system of marking dependent nouns for the type of relationship they bear to their heads". Cases should be distinguished from thematic roles such as "agent" and "patient". They are often closely related , and in languages such as Latin, several thematic roles are realised by a somewhat fixed case for deponent verbs, but cases are a syntagmatic/phrasal category, and thematic roles are the function of a syntagma/phrase in a larger structure. Languages having cases often exhibit free word order, as thematic roles are not required to be marked by position in the sentence. History. It is widely accepted that the Ancient Greeks had a certain idea of the forms of a name in their own language. A fragment of Anacreon seems to prove this. Nevertheless, it cannot be inferred that  the Ancient Greeks really knew what grammatical cases were. Grammatical cases were first recognized by the Stoics and from some philosophers of the Peripatetic school. The advancements of those philosophers were later employed by the philologists of the Alexandrian school. Etymology. The English word "case" used in this sense comes from the Latin , which is derived from the verb , "to fall", from the Proto-Indo-European root "". The Latin word is a calque of the Greek , , lit. "falling, fall". The sense is that all other cases are considered to have "fallen" away from the nominative. This imagery is also reflected  in the word "declension", from Latin , "to lean", from the PIE root "". The equivalent to "case" in several other European languages also derives from "casus", including in French, in Italian, in Spanish, in Portuguese and in German. The Russian word ("padyézh") is a calque from Greek and similarly contains a root meaning "fall", and the German and Czech simply mean "fall", and are used for both the concept of grammatical case and to refer to physical falls. The Finnish equivalent is , whose main meaning is "position" or "place". Indo-European languages. Although not very prominent in modern English, cases featured  much more saliently in Old English and other ancient Indo-European languages, such as Latin, Old Persian, Ancient Greek, and Sanskrit. Historically, the Indo-European languages had eight morphological cases, though modern languages typically have fewer, using prepositions and word order to convey information that had previously been conveyed using distinct noun forms. Among modern languages, cases still feature prominently in most of the Balto-Slavic languages (except Macedonian and Bulgarian), with most having six to eight cases, as well as Icelandic, German and Modern Greek, which have four. In German, cases are mostly marked on articles and adjectives, and  less so on nouns. In Icelandic, articles, adjectives, personal names and nouns are all marked for case, making it, among other things, the living Germanic language that could be said to most closely resemble Proto-Germanic. The eight historical Indo-European cases are as follows, with examples either of the English case or of the English syntactic alternative to case: All of the above are just rough descriptions; the precise distinctions vary significantly from language to language, and as such they are often more complex. Case is based fundamentally on changes to the noun to indicate the noun's role  in the sentence – one of the defining features of so-called fusional languages. Old English was a fusional language, but Modern English does not work this way. Modern English. Modern English has largely abandoned the inflectional case system of Proto-Indo-European in favor of analytic constructions. The personal pronouns of Modern English retain morphological case more strongly than any other word class (a remnant of the more extensive case system of Old English). For other pronouns, and all nouns, adjectives, and articles, grammatical function is indicated only by word order, by prepositions, and by the "Saxon genitive" ("-'s"). Taken  as a whole, English personal pronouns are typically said to have three morphological cases: Most English personal pronouns have five forms: the nominative case form, the oblique case form, a distinct "reflexive" or "intensive" form (such as "myself", "ourselves") which is based upon the possessive determiner form but is coreferential to a preceding instance of nominative or oblique, and the possessive case forms, which include both a "determiner" form (such as "my", "our") and a predicatively-used "independent" form (such as "mine", "ours") which is distinct (with two exceptions: the third person singular masculine "he" and the third person singular  neuter "it", which use the same form for both determiner and independent ["his car", "it is his"]). The interrogative personal pronoun "who" exhibits the greatest diversity of forms within the modern English pronoun system, having definite nominative, oblique, and genitive forms ("who", "whom", "whose") and equivalently-coordinating indefinite forms ("whoever", "whomever", and "whosever"). Though English "pronouns" can have subject and object forms (he/him, she/her), "nouns" show only a singular/plural and a possessive/non-possessive distinction (e.g. "chair", "chairs", "chair's", "chairs"'); there is no manifest difference in the form of "chair" between "The chair is here." (subject ) and "I have the chair." (direct object), a distinction made instead by word order and context. Hierarchy of cases. Cases can be ranked in the following hierarchy, where a language that does not have a given case will tend not to have any cases to the right of the missing case: This is, however, only a general tendency. Many forms of Central German, such as Colognian and Luxembourgish, have a dative case but lack a genitive. In Irish nouns, the nominative and accusative have fallen together, whereas the dative–locative has remained separate in some paradigms; Irish also has genitive  and vocative cases. In many modern Indo-Aryan languages, the accusative, genitive, and dative have merged to an oblique case, but many of these languages still retain vocative, locative, and ablative cases. Old English had an instrumental case, but neither a locative nor a prepositional case. Case order. The traditional case order (nom-gen-dat-acc) was expressed for the first time in "The Art of Grammar" in the 2nd century BC: Latin grammars, such as "Ars grammatica", followed the Greek tradition, but added the ablative case of Latin. Later other European languages also followed that Graeco-Roman tradition. However , for some languages, such as Latin, due to case syncretism the order may be changed for convenience, where the accusative or the vocative cases are placed after the nominative and before the genitive. For example: For similar reasons, the customary order of the four cases in Icelandic is nominative–accusative–dative–genitive, as illustrated below: Case concord systems. In the most common case concord system, only the head-word (the noun) in a phrase is marked for case. This system appears in many Papuan languages as well as in Turkic, Mongolian, Quechua, Dravidian, Indo-Aryan, and other languages. In Basque  and various Amazonian and Australian languages, only the phrase-final word (not necessarily the noun) is marked for case. In many Indo-European, Finnic, and Semitic languages, case is marked on the noun, the determiner, and usually the adjective. Other systems are less common. In some languages, there is double-marking of a word as both genitive (to indicate semantic role) and another case such as accusative (to establish concord with the head noun). Declension paradigms. Declension is the process or result of altering nouns to the correct grammatical cases. Languages with rich nominal inflection (use grammatical cases for many  purposes) typically have a number of identifiable declension classes, or groups of nouns with a similar pattern of case inflection or declension. Sanskrit has six declension classes, whereas Latin is traditionally considered to have five, and Ancient Greek three. For example, Slovak has fifteen noun declension classes, five for each gender (the number may vary depending on which paradigms are counted or omitted, this mainly concerns those that modify declension of foreign words; refer to article). In Indo-European languages, declension patterns may depend on a variety of factors, such as gender, number, phonological environment, and irregular historical factors. Pronouns  sometimes have separate paradigms. In some languages, particularly Slavic languages, a case may contain different groups of endings depending on whether the word is a noun or an adjective. A single case may contain many different endings, some of which may even be derived from different roots. For example, in Polish, the genitive case has "-a, -u, -ów, -i/-y, -e-" for nouns, and "-ego, -ej, -ich/-ych" for adjectives. To a lesser extent, a noun's animacy or humanness may add another layer of complexity. For example, in Russian: vs. and Examples. Australian Aboriginal Languages. Australian languages represent a diversity of  case paradigms in terms of their alignment (i.e. nominative-accusative vs. ergative-absolutive) and the morpho-syntactic properties of case inflection including where/how many times across a noun phrase the case morphology will appear. For typical r-expression noun phrases, most Australian languages follow a basic ERG-ABS template with additional cases for peripheral arguments; however, many Australian languages, the function of case marking extends beyond the prototypical function of specifying the syntactic and semantic relation of an NP to a predicate. Dench and Evans (1988) use a five-part system for categorizing the functional roles of case marking  in Australian languages. They are enumerated below as they appear in Senge (2015): To illustrate this paradigm in action, take the case-system of Wanyjirra for whose description Senge invokes this system. Each of the case markers functions in the prototypical relational sense, but many extend into these additional functions: Wanyjirra is an example of a language in which case marking occurs on all sub-constituents of the NP; see the following example in which the demonstrative, head, and quantifier of the noun phrase all receive ergative marking: However, this is by no means always the case or even the  norm for Australian languages. For many, case-affixes are considered special-clitics (i.e. phrasal-affixes, see Anderson 2005) because they have a singular fixed position within the phrase. For Bardi, the case marker usually appears on the first phrasal constituent while the opposite is the case for Wangkatja (i.e. the case marker is attracted to the rightmost edge of the phrase). See the following examples respectively: Bardi Wangkatja Basque. Basque has the following cases, with examples given in the indefinite, definite singular, definite plural, and definite close plural of the word "etxe", "house", "home": Some of them can be re -declined, even more than once, as if they were nouns (usually, from the genitive locative case), although they mainly work as noun modifiers before a noun clause: German. In German, grammatical case is largely preserved in the articles and adjectives, but nouns have lost many of their original endings. Below is an example of case inflection in German using the masculine definite article and one of the German words for "sailor". An example with the feminine definite article with the German word for "woman". An example with the neuter definite article with the German word for "book". Proper names for  cities have two genitive nouns: Hindi-Urdu. Hindi-Urdu (Hindustani) has three noun cases, the "nominative," "oblique case," and the "vocative case". The "vocative case" is now obsolete and the oblique case doubles as the vocative case. The pronoun cases that Hindi-Urdu has are the "nominative", "ergative", "accusative, dative", and two "oblique" cases. The case forms which do not exist for certain pronouns are constructed using primary postpositions (or other grammatical particles) and the oblique case (shown in parentheis in the table below). The other cases are constructed adpositionally using the case-marking postpositions using the nouns and pronouns  in their oblique cases. The oblique case is used exclusively with these 8 case-marking postpositions of Hindi-Urdu forming 10 grammatical cases, which are: "ergative" ने (ne), "dative" and "accusative" को (ko), "instrumental" and "ablative" से (se), "genitive" का (kā), "inessive" में (mẽ), "adessive" पे (pe), "terminative" तक (tak), "semblative" सा (sā). Latin. An example of a Latin case inflection is given below, using the singular forms of the Latin term for "cook", which belongs to Latin's second declension class. The Romance languages have largely abandoned or simplified the grammatical cases of Latin. Much like English, most Romance  case markers survive only in pronouns. Lithuanian. Typically in Lithuanian, only the inflection changes for the seven different grammatical cases: Hungarian. Hungarian declension is relatively simple with regular suffixes attached to the vast majority of nouns. The following table lists all of the cases used in Hungarian. Russian. An example of a Russian case inflection is given below (with explicit stress marks), using the singular forms of the Russian term for "sailor", which belongs to Russian's first declension class. Up to ten additional cases are identified by linguists, although today all of them are either incomplete (do not apply  to all nouns or do not form full word paradigm with all combinations of gender and number) or degenerate (appear identical to one of the main six cases). The most recognized additional cases are locative (), partitive (), and two forms of vocative — old () and neo-vocative (). Sometimes, so called count-form (for some countable nouns after numerals) is considered to be a sub-case. See details. Sanskrit. Grammatical case was analyzed extensively in Sanskrit. The grammarian Pāṇini identified six semantic roles or "kāraka", which are related to the following eight Sanskrit cases in order: For example, in the following sentence "leaf  is the agent (kartā", nominative case), "tree" is the source ("apādāna", ablative case), and "ground" is the locus ("adhikaraṇa", locative case). The declensions are reflected in the morphemes "-āt", "-am", and "-au" respectively. However, the cases may be deployed for other than the default thematic roles. A notable example is the passive construction. In the following sentence, "Devadatta" is the "kartā", but appears in the instrumental case, and "rice", the "karman", object, is in the nominative case (as subject of the verb). The declensions are reflected in the morphemes "-ena" and "-am". Tamil. The Tamil case system is analyzed in  native and missionary grammars as consisting of a finite number of cases. The usual treatment of Tamil case (Arden 1942) is one in which there are seven cases: nominative (first case), accusative (second case), instrumental (third), dative (fourth), ablative (fifth), genitive (sixth), and locative (seventh). In traditional analyses, there is always a clear distinction made between post-positional morphemes and case endings. The vocative is sometimes given a place in the case system as an eighth case, but vocative forms do not participate in usual morphophonemic alternations and do not govern the use of any postpositions. Modern grammarians, however, argue  that this eight-case classification is coarse and artificial and that Tamil usage is best understood if each suffix or combination of suffixes is seen as marking a separate case. Turkish. Modern Turkish has six cases (In Turkish "İsmin hâlleri"). The accusative can exist only in the noun(whether it is derived from a verb or not). For example, "Arkadaşlar bize gelmeyi düşünüyorlar." (Friends are thinking of coming to us). The dative can exist only in the noun (whether it is derived from a verb or not). For example, "Bol bol kitap okumaya çalışıyorum." (I try to read a lot of  books). Evolution. As languages evolve, case systems change. In early Ancient Greek, for example, the genitive and ablative cases of given names became combined, giving five cases, rather than the six retained in Latin. In modern Hindi, the Sanskrit cases have been reduced to three: a direct case (for subjects and direct objects) and oblique case, and a vocative case. In English, apart from the pronouns discussed above, case has vanished altogether except for the possessive/non-possessive dichotomy in nouns. The evolution of the treatment of case relationships can be circular. Adpositions can become unstressed and sound like they  are an unstressed syllable of a neighboring word. A postposition can thus merge into the stem of a head noun, developing various forms depending on the phonological shape of the stem. Affixes can then be subject to various phonological processes such as assimilation, vowel centering to the schwa, phoneme loss, and fusion, and these processes can reduce or even eliminate the distinctions between cases. Languages can then compensate for the resulting loss of function by creating adpositions, thus coming full circle. Recent experiments in agent-based modeling have shown how case systems can emerge and evolve in a population of  language users. The experiments demonstrate that language users may introduce new case markers to reduce the cognitive effort required for semantic interpretation, hence facilitating communication through language. Case markers then become generalized through analogical reasoning and reuse. Linguistic typology. Morphosyntactic alignment. Languages are categorized into several case systems, based on their "morphosyntactic alignment"—how they group verb agents and patients into cases: The following are systems that some languages use to mark case instead of, or in addition to, declension: Language families. The lemma form of words, which is the form chosen by convention as the canonical form of a word , is usually the most unmarked or basic case, which is typically the nominative, trigger, or absolutive case, whichever a language may have.