DiaphonemeA diaphoneme is an abstract phonological unit that identifies a correspondence between related sounds of two or more varieties of a language or language cluster. For example, some English varieties contrast the vowel of late (/eː/) with that of wait or eight (/ɛɪ/). Other English varieties contrast the vowel of late or wait (/eː/) with that of eight (/ɛɪ/). This non-overlapping pair of phonemes from two different varieties can be reconciled by positing three different diaphonemes: A first diaphoneme for words like late (⫽e⫽), a second diaphoneme for words like wait (⫽ei⫽), and a third diaphoneme for words like eight (⫽ex⫽).
Rhoticity in EnglishRhoticity in English is the pronunciation of the historical rhotic consonant /r/ by English speakers. The presence or absence of rhoticity is one of the most prominent distinctions by which varieties of English can be classified. In rhotic varieties, the historical English /r/ sound is preserved in all pronunciation contexts. In non-rhotic varieties, speakers no longer pronounce /r/ in postvocalic environments: when it is immediately after a vowel and not followed by another vowel.
Cot–caught mergerThe cot–caught merger, also known as the merger or low back merger, is a sound change present in some dialects of English where speakers do not distinguish the vowel phonemes in words like cot versus caught. Cot and caught (along with bot and bought, pond and pawned, etc.) is an example of a minimal pair that is lost as a result of this sound change. The phonemes involved in the cot–caught merger, the low back vowels, are typically represented in the International Phonetic Alphabet as /ɒ/ and /ɔ/, respectively (or, in North America, co-occurring with the father–bother merger, as /ɑ/ and /ɔ/).
Minimal pairIn phonology, minimal pairs are pairs of words or phrases in a particular language, spoken or signed, that differ in only one phonological element, such as a phoneme, toneme or chroneme, and have distinct meanings. They are used to demonstrate that two phones represent two separate phonemes in the language. Many phonologists in the middle part of the 20th century had a strong interest in developing techniques for discovering the phonemes of unknown languages, and in some cases, they set up writing systems for the languages.
Language changeLanguage change is variation over time in a language's features. It is studied in several subfields of linguistics: historical linguistics, sociolinguistics, and evolutionary linguistics. Traditional theories of historical linguistics identify three main types of change: systematic change in the pronunciation of phonemes, or sound change; borrowing, in which features of a language or dialect are altered as a result of influence from another language or dialect; and analogical change, in which the shape or grammatical behavior of a word is altered to more closely resemble that of another word.
Sound changeA sound change, in historical linguistics, is a change in the pronunciation of a language. A sound change can involve the replacement of one speech sound (or, more generally, one phonetic feature value) by a different one (called phonetic change) or a more general change to the speech sounds that exist (phonological change), such as the merger of two sounds or the creation of a new sound. A sound change can eliminate the affected sound, or a new sound can be added.
Assimilation (phonology)Assimilation is a sound change in which some phonemes (typically consonants or vowels) change to become more similar to other nearby sounds. A common type of phonological process across languages, assimilation can occur either within a word or between words. It occurs in normal speech but becomes more common in more rapid speech. In some cases, assimilation causes the sound spoken to differ from the normal pronunciation in isolation, such as the prefix in- of English input pronounced with phonetic [m] rather than [n].
