Editing Phoneme (section)

==Examples and notation==
The English words ''cell'' and ''set'' have the exact same sequence of sounds, except for being different in their final consonant sounds: thus, {{IPA|/sɛl/}} versus {{IPA|/sɛt/}} in the [[International Phonetic Alphabet]] (IPA), a writing system that can be used to represent phonemes. Since {{IPA|/l/}} and {{IPA|/t/}} alone distinguish certain words from others, they are each examples of phonemes of the English language. Specifically they are consonant phonemes, along with {{IPA|/s/}}, while {{IPA|/ɛ/}} is a vowel phoneme. The spelling of English does not strictly conform to its phonemes, so that the words ''knot'', ''nut'', and ''gnat'', regardless of spelling, all share the consonant phonemes {{IPA|/n/}} and {{IPA|/t/}}, differing only by their internal vowel phonemes: {{IPA|/ɒ/}}, {{IPA|/ʌ/}}, and {{IPA|/æ/}}, respectively. Similarly, {{IPA|/pʊʃt/}} is the notation for a sequence of four phonemes, {{IPA|/p/}}, {{IPA|/ʊ/}}, {{IPA|/ʃ/}}, and {{IPA|/t/}}, that together constitute the word ''pushed''. 

Sounds that are perceived as phonemes vary by languages and dialects, so that {{IPAblink|n|audio=y}} and {{IPAblink|ŋ|audio=y}} are separate phonemes in English since they distinguish words like ''sin'' from ''sing'' ({{IPA|/sɪn/}} versus {{IPA|/sɪŋ/}}), yet they comprise a single phoneme in some other languages, such as Spanish, in which {{IPA|[pan]}} and {{IPA|[paŋ]}} for instance are merely interpreted by Spanish speakers as regional or dialect-specific ways of pronouncing the same word (''pan'': the Spanish word for "bread"). Such spoken variations of a single phoneme are known by linguists as ''[[allophone]]s''. Linguists use [[Slash (punctuation)|slashes]] in the IPA to transcribe phonemes but [[square brackets]] to transcribe more precise pronunciation details, including allophones; they describe this basic distinction as ''phonemic''{{efn|Or more rarely, ''phonematic''.<ref>{{cite journal|journal=Classical Philology|volume=40|number=1|date=January 1945|page=47|quote=Professor Whatmough’s assault on the terms “phonemic” and “phonemics” seemed to me, as to others, pedantic. So it is a pleasure to discover that his antipathy to these now well-established terms is not so deep rooted and consistent as one would suppose from his words in ''CP'', XXXVIII (1943), 211: “Nobody says ''mathemics'' instead of ''mathematics''; and I, for one, do not say, and never shall, ''phonemics'' for ''phonematics'' or ''phonemic'' for ''phonematic''.” In happening to re-read an earlier article of his in the ''Mélanges linguistiques offerts à M. Holger Pedersen'' (1937),. I find him beginning a sentence (p. 46) “Ideally the phonemic system of a language. . . . .”|title="Phonemics" versus "Phonematics"|first=Carl Darling|last=Buck|authorlink=Carl Darling Buck|publisher=University of Chicago|doi=10.1086/362860 }}</ref><ref>{{cite web|url=https://www.collinsdictionary.com/dictionary/english/phonematic|title=phonematic|website=Collins}}</ref>}} versus ''phonetic''. Thus, the pronunciation patterns of ''tap'' versus ''tab'', or ''pat'' versus ''bat'', can be represented phonemically and are written between slashes (including {{IPA|/p/}}, {{IPA|/b/}}, etc.), while nuances of exactly how a speaker pronounces {{IPA|/p/}} are phonetic and written between brackets, like {{IPA|[p]}} for the ''p'' in ''spit'' versus {{IPA|[pʰ]}} for the ''p'' in ''pit'', which in English is an [[aspirated consonant|aspirated]] allophone of /p/ (i.e., pronounced with an extra burst of air).

There are many views as to exactly what phonemes are and how a given language should be analyzed in phonemic terms. Generally, a phoneme is regarded as an [[abstraction]] of a set (or [[equivalence class]]) of spoken sound variations that are nevertheless perceived as a single basic unit of sound by the ordinary native speakers of a given language. While phonemes are considered an abstract [[underlying representation]] for sound segments within words, the corresponding [[phonetic]] realizations of those phonemes&mdash;each phoneme with its various allophones&mdash;constitute the surface form that is actually uttered and heard. Allophones each have technically different articulations inside particular words or particular [[Phonetic environment|environments within words]], yet these differences do not create any [[semantics|meaningful]] distinctions. Alternatively, at least one of those articulations could be feasibly used in all such words with these words still being recognized as such by users of the language. An example in [[American English]] is that the sound spelled with the symbol ''t'' is usually [[Articulatory phonetics|articulated]] with a [[glottal stop]] {{IPA|[ʔ]}} (or a similar glottalized sound) in the word ''cat'', an [[alveolar flap]] {{IPA|[ɾ]}} in ''dating'', an [[voiceless alveolar plosive|alveolar plosive]] {{IPA|[t]}} in ''stick'', and an [[aspirated consonant|aspirated]] alveolar plosive {{IPA|[tʰ]}} in ''tie''; however, American speakers perceive or "hear" all of these sounds (usually with no conscious effort) as merely being allophones of a single phoneme: the one traditionally represented in the IPA as {{IPA|/t/}}.

For computer-typing purposes, [[Comparison of ASCII encodings of the International Phonetic Alphabet|systems]] such as [[X-SAMPA]] exist to represent IPA symbols using only [[ASCII]] characters. However, descriptions of particular languages may use different conventional symbols to represent the phonemes of those languages. For languages whose writing systems employ the [[phonemic principle]], ordinary letters may be used to denote phonemes, although this approach is often imperfect, as pronunciations naturally shift in a language over time, rendering previous spelling systems outdated or no longer closely representative of the sounds of the language (see {{Section link||Correspondence between letters and phonemes}} below).