Metathesis is one of several linguistic phenomenons recognized in phonology. Such phenomenons typically involve the addition, deletion or reordering of sounds, letters or syllables in a word or phrase. Specifically, metathesis occurs when the syllables of a particular word are changed, reversed or otherwise reordered to make a new word, usually closely related to the original. For example, in English, metathesis most often occurs in the pronunciation of words such as "cavalry", which is commonly pronounced "calvary," with the sounds of the middle syllable reordered.
To further explain metathesis and similar linguistic phenomenons, researchers look to phonology. Phonology is the overall study of the sounds and associated rules for various languages. Within phonology, linguistic experts have identified specific, recurring patterns relative to the interaction of various sounds in a particular language. Virtually all languages feature examples of metathesis or other linguistic patterns, either in spoken or written communications.
Through the continuing study of phonology, experts have identified occurrences of phenomenons such as metathesis, epenthesis and Spoonerisms in both written and spoken language throughout the world. Although they are closely related and easily confused, sound changes owing to metathesis should not be confused with other linguistic phenomenons. Many characteristics appear to be similar, although key characteristics clearly delineate each phenomenon.
Epenthesis involves the addition of letters, sounds or entire syllables to a word. Poetry and other metered literature are the most common reasons for changing a word via epenthesis. Spoonerisms exchange the initial sounds or syllables of two adjacent words within a sentence. First identified by a clergyman named William Spooner, such changes typically are the result of a person who has unintentionally misspoken a sentence.
Alternatively, metathesis simply takes the existing sounds and syllables in a word and changes their placement within the word. No additional letters, sounds or syllables are added. Other words within the sentence remain unchanged and are largely unaffected by the change to a single word. In some cases, the phenomenon occurs merely as a difference in dialects.
One such illustration is the differences between British and American words such as "theater." Americans and British alike pronounce the word with the same meter and accented syllables. Spelling, on the other hand, changes based on country of origin. British spelling of the word reorders the last two letters “er” to “re,” resulting in the word "theatre."
Further examples occur in both verbal and written form, often as the lexicon of a language evolves. "Asterisk" in English has evolved over time to become pronounced as "asteriks," or "asterix." The French have evolved formage to fromage. Many instances of such metathesis grow from initial misspellings or mispronunciations of existing words. Over time, incorrect spellings and pronunciations often become accepted as informal variations of a particular word.