Language

===Sounds and symbols===
{{main|Phonology|Writing}}
{{multiple image
| align     = right
| direction = vertical
| width     = 150
| image1    = ManSpec.png
| caption1  = A spectrogram showing the sound of the spoken English word "man", which is written phonetically as {{ipa|[mæn]}}. In flowing speech, there is no clear division between segments, only a smooth transition as the vocal apparatus moves.
| image3    = Hangul wi.svg
| caption3  = The syllable "wi" in the [[Hangul]] script
| image4    = KSL wi.jpg
| caption4  = The sign for "wi" in [[Korean Sign Language]] (see [[Korean manual alphabet]])
}}

Depending on modality, language structure can be based on systems of sounds (speech), gestures (sign languages), or graphic or tactile symbols (writing). The ways in which languages use sounds or signs to construct meaning are studied in [[phonology]].<ref>{{harvcoltxt|Goldsmith|1995}}</ref>

Sounds as part of a linguistic system are called [[phonemes]].<ref>{{harvcoltxt|International Phonetic Association|1999|p=27}}</ref> Phonemes are abstract units of sound, defined as the smallest units in a language that can serve to distinguish between the meaning of a pair of minimally different words, a so-called [[minimal pair]]. In English, for example, the words ''bat'' {{ipa|[bæt]}} and ''pat'' {{ipa|[pʰæt]}} form a minimal pair, in which the distinction between {{IPA|/b/}} and {{IPA|/p/}} differentiates the two words, which have different meanings. However, each language contrasts sounds in different ways. For example, in a language that does not distinguish between voiced and unvoiced consonants, the sounds {{IPA|[p]}} and {{IPA|[b]}} (if they both occur) could be considered a single phoneme, and consequently, the two pronunciations would have the same meaning. Similarly, the English language does not distinguish phonemically between [[aspiration (linguistics)|aspirated and non-aspirated]] pronunciations of consonants, as many other languages like [[Korean language|Korean]] and [[Hindi]] do: the unaspirated {{IPA|/p/}} in ''spin'' {{ipa|[spɪn]}} and the aspirated {{IPA|/p/}} in ''pin'' {{ipa|[pʰɪn]}} are considered to be merely different ways of pronouncing the same phoneme (such variants of a single phoneme are called [[allophones]]), whereas in [[Mandarin Chinese]], the same difference in pronunciation distinguishes between the words {{ipa|[pʰá]}} 'crouch' and {{ipa|[pá]}} 'eight' (the accent above the á means that the vowel is pronounced with a high tone).<ref name="Trask214"/>

All [[oral language|spoken languages]] have phonemes of at least two different categories, [[vowels]] and [[consonants]], that can be combined to form [[syllable]]s.<ref name="MacMahon5"/> As well as segments such as consonants and vowels, some languages also use sound in other ways to convey meaning. Many languages, for example, use [[stress (linguistics)|stress]], [[pitch accent|pitch]], [[Vowel length|duration]], and [[tonal language|tone]] to distinguish meaning. Because these phenomena operate outside of the level of single segments, they are called [[suprasegmental]].<ref>{{harvcoltxt|International Phonetic Association|1999|p=4}}</ref> Some languages have only a few phonemes, for example, [[Rotokas language|Rotokas]] and [[Pirahã language]] with 11 and 10 phonemes respectively, whereas languages like [[Taa language#Phonology|Taa]] may have as many as 141 phonemes.<ref name="Trask214">{{harvcoltxt|Trask|2007|p=214}}</ref> In [[sign language]]s, [[Phoneme#Phonemes in sign languages|the equivalent to phonemes]] (formerly called [[chereme]]s) are defined by the basic elements of gestures, such as hand shape, orientation, location, and motion, which correspond to manners of articulation in spoken language.<ref>Stokoe, William C. (1960). ''Sign Language Structure: An Outline of the Visual Communication Systems of the American Deaf,'' Studies in linguistics: Occasional papers (No. 8). Buffalo: Dept. of Anthropology and Linguistics, University of Buffalo.</ref><ref>[[William Stokoe|Stokoe, William C.]]; [[Dorothy C. Casterline]]; [[Carl G. Croneberg]] (1965). ''A dictionary of American sign languages on linguistic principles.'' Washington, D.C.: Gallaudet College Press</ref><ref>{{harvcoltxt|Sandler|Lillo-Martin|2001|pp=539–540}}</ref>

[[Writing system]]s represent language using visual symbols, which may or may not correspond to the sounds of spoken language. The [[Latin alphabet]] (and those on which it is based or that have been derived from it) was originally based on the representation of single sounds, so that words were constructed from letters that generally denote a single consonant or vowel in the structure of the word. In [[syllabary|syllabic scripts]], such as the [[Inuktitut]] syllabary, each sign represents a whole syllable. In [[logographic]] scripts, each sign represents an entire word,<ref>{{harvcoltxt|Trask|2007|p=326}}</ref> and will generally bear no relation to the sound of that word in spoken language.

Because all languages have a very large number of words, no purely logographic scripts are known to exist. Written language represents the way spoken sounds and words follow one after another by arranging symbols according to a pattern that follows a certain direction. The direction used in a writing system is entirely arbitrary and established by convention. Some writing systems use the horizontal axis (left to right as the Latin script or right to left as the [[Arabic script]]), while others such as traditional Chinese writing use the vertical dimension (from top to bottom). A few writing systems use opposite directions for alternating lines, and others, such as the ancient Maya script, can be written in either direction and rely on graphic cues to show the reader the direction of reading.<ref name="Coulmas">{{harvcoltxt|Coulmas|2002}}</ref>

In order to represent the sounds of the world's languages in writing, linguists have developed the [[International Phonetic Alphabet]], designed to represent all of the discrete sounds that are known to contribute to meaning in human languages.<ref>{{harvcoltxt|Trask|2007|p=123}}</ref>