Editing Phoneme (section)

==Restrictions on occurrence==
{{Main|Phonotactics}}
Languages do not generally allow words or [[syllable]]s to be built of any arbitrary sequences of phonemes. There are [[phonotactics|phonotactic]] restrictions on which sequences of phonemes are possible and in which environments certain phonemes can occur. Phonemes that are significantly limited by such restrictions may be called ''restricted phonemes''.

In English, examples of such restrictions include the following:

* {{IPA|/ŋ/}}, as in ''si'''ng''''', occurs only at the end of a syllable, never at the beginning (in many other languages, such as [[Māori language|Māori]], [[Swahili language|Swahili]], [[Tagalog language|Tagalog]], [[Thai language|Thai]], and [[Tswana language|Setswana]], {{IPA|/ŋ/}} can appear word-initially).
* {{IPA|/h/}} occurs only at the beginning of a syllable, never at the end (a few languages, such as [[Arabic language|Arabic]] and [[Romanian Language|Romanian]], allow {{IPA|/h/}} syllable-finally).
* In [[rhotic and non-rhotic accents|non-rhotic dialects]], {{IPA|/ɹ/}} can occur immediately only before a vowel, never before a consonant.
* {{IPA|/w/}} and {{IPA|/j/}} occur only before a vowel, never at the end of a syllable (except in interpretations in which a word like ''boy'' is analyzed as {{IPA|/bɔj/}}).

Some phonotactic restrictions can alternatively be analyzed as cases of neutralization. See [[#Neutralization and archiphonemes|Neutralization and archiphonemes]] below, particularly the example of the occurrence of the three English nasals before stops.