Definition of "Metathesis" in Phonetics

Metathesis sounds complicated but it's a very common aspect of the English language. It is the transposition within a word of letters, sounds or syllables. D. Minkova and R. Stockwell comment in "English Words: History and Structure" (2009) that "Although metathesis occurs commonly in many languages, the phonetic conditions for it can be identified only in very general terms: Certain sound combinations, often involving [r], are more susceptible to metathesis than others." The word "metathesis" comes from the Greek word meaning to transpose. It's also known as a permutation.

Examples and Observations on Metathesis

• "Wasp used to be 'waps'; bird used to be 'brid' and horse used to be 'hros.' Remember this the next time you hear someone complaining about 'aks' for ask or 'nucular' for nuclear, or even 'perscription.' It's called metathesis, and it's a very common, perfectly natural process." (David Shariatmadari, "Eight Pronunciation Errors That Made the English Language What It Is Today" The Guardian, March 2014)
• From Orpah to Oprah
  "The order of sounds can be changed in a process called metathesis. 'Tax' and 'task' are variant developments of a single form, with the [ks] (represented in spelling by x) metathesized in the second word to [sk]—tax, after all, is a task all of us must meet. The television personality Oprah was originally named Orpah, after one of the two daughters-in-law of the Biblical Naomi (Ruth 1.4), but the 'rp' got metathesized to 'pr,' producing the well-known name. The metathesis of a sound and a syllable boundary in the word 'another' leads to the reinterpretation of original 'an other' as 'a nother,' especially in the expression 'a whole nother thing.'" (John Algeo and Thomas Pyles, "The Origins and Development of the English Language", 2010)
• Typical Shifters
  "Other typical shifters are nasal sounds. For example, if [m] and [n] find themselves in the same word, they might swap places, too—'renumeration' in place of 'remuneration,' 'aminal' in place of 'animal' and 'emeny' in place of 'enemy.' Most of us, I suspect, are guilty of the pronunciation 'anenome.' These days, historically accurate 'anemone' is rare and to many sounds rather odd." (Kate Burridge, "Gift of the Gob: Morsels of English Language History, 2011)
• Spaghetti/Psketti
  "We played well together in the earliest days, though occasionally our jocund recreation became antagonistic. Tony might hound me about a particular piece of verbal stupidity, some word that I could not get my mouth around, such as 'spaghetti" or 'radiator' (which came out 'pisketti' and 'elevator')." (Christopher Lukas, "Blue Genes: A Memoir of Loss and Survival", 2008)
• Cannibal/Caliban
  "A famous example from Shakespeare's 'The Tempest' is the figure of Caliban whose name originates from a phonological metathesis of /n/ and /l/ in 'cannibal.'" (Heinrich F. Plett, Literary Rhetoric: Concepts-Structures-Analyses", 2009)
• Metathesis in the Pronunciation of "Ask" as /aks/
  "While the pronunciation /aks/ for 'ask' is not considered standard, it is a very common regional pronunciation with a long history. The Old English verb ' ascian' underwent a normal linguistic process called metathesis sometime in the 14th century. Metathesis is what occurs when two sounds or syllables switch places in a word. This happens all the time in spoken language (think 'nuclear' pronounced as /nukular/ and 'asterisk' pronounced as /asteriks/).
  "Metathesis is usually a slip of the tongue, but (as in the cases of /asteriks/ and /nukular/) it can become a variant of the original word.
  "In American English, the /aks/ pronunciation was originally dominant in New England. The popularity of this pronunciation faded in the North early in the 19th century as it became more common in the South. Today the pronunciation is perceived in the U.S. as either Southern or African-American. Both of these perceptions underestimate the popularity of the form." ("ax-ask," Mavens' Word of the Day, Dec. 16, 1999)
  "Metathesis is a common linguistic process around the world and does not arise from a defect in speaking. Nevertheless, /aks/ has become stigmatized as substandard—a fate that has befallen other words, like 'ain't,' that were once perfectly acceptable in educated society." ("The American Heritage Guide to Contemporary Usage and Style", 2005)