Editing Adposition (section)

===Case affixes===

Some [[grammatical case]] markings have a similar function to adpositions; a case affix in one language may be equivalent in meaning to a preposition or postposition in another. For example, in English, the agent of a [[passive voice|passive]] construction is marked by the preposition ''by'', while in [[Russian grammar|Russian]] it is marked by the use of the [[instrumental case]]. Sometimes such equivalences exist within a single language; for example, the [[genitive]] case in [[German grammar|German]] is often interchangeable with a phrase using the preposition ''von'' (just as in English, the preposition ''of'' is often interchangeable with the [[English possessive|possessive suffix]] ''{{`s}}'').

Adpositions combine [[syntax|syntactically]] with their complement, whereas case markings combine with a noun [[morphology (linguistics)|morphologically]]. In some instances it may not be clear which applies; the following are some possible means of making such a distinction:
* Two adpositions can usually be joined with a [[coordinating conjunction]] and share a single complement (''of and for the people''), whereas this is generally not possible with case affixes;
* One adposition can usually combine with two coordinated complements (''of the city and the world''), whereas a case affix would need to be repeated with each noun ([[Latin language|Latin]] ''urbis et orbis'', not *urb- et orbis'');
* Case markings combine primarily with nouns, whereas adpositions can combine with (nominalized) phrases of different categories;
* A case marking usually appears directly on the noun, but an adposition can be separated from the noun by other words;
* Within the noun phrase, determiners and adjectives may agree with the noun in case ('''case spreading'''), but an adposition only appears once;
* A language can have hundreds of adpositions (including complex adpositions), but no language has that many distinct morphological cases.

Even so, a clear distinction cannot always be made. For example, the post-nominal elements in [[Japanese language|Japanese]] and [[Korean language|Korean]] are sometimes called case particles and sometimes postpositions. Sometimes they are analyzed as two different groups because they have different characteristics (e.g., the ability to combine with focus particles), but in such analysis, it is unclear which words should fall into which group.

[[Turkish grammar|Turkish]], [[Finnish grammar|Finnish]] and [[Hungarian grammar|Hungarian]] have both extensive case-marking and postpositions, but there is evidence to help distinguish the two:
* Turkish: (case) ''sinema'''ya''''' (cinema-''dative'', "to the cinema") vs. (postposition) ''sinema '''için''''' ("for the cinema")
* Finnish: (case) ''talo'''ssa''''' (house-''[[inessive]]'', "in the house") vs. (postposition) ''talon '''edessä''''' (house-''genitive'' in front, "in front of the house")
* Hungarian: (case) ''tető'''n''''' (roof-''[[superessive]]'', "on the roof") vs. (postposition) ''tető '''alatt''''' ("under the roof")

In these examples, the case markings form a word with their hosts (as shown by [[vowel harmony]], other word-internal effects and agreement of adjectives in Finnish), while the postpositions are independent words. As is seen in the last example, adpositions are often used in conjunction with case affixes – in languages that have a case, a given adposition usually takes a complement in a particular case, and sometimes (as has been seen [[#Grammatical properties|above]]) the choice of the case helps specify the meaning of the adposition.