Esperanto phonology

The creator of Esperanto, L. L. Zamenhof, illustrated Esperanto pronunciation by comparing its letters with their equivalents in several major European languages and declaring a principle of "one letter, one sound".

With over a century of use, Esperanto has developed a phonological norm, including accepted details of phonetics,phonotactics, and intonation, so that it is now possible to speak of proper Esperanto pronunciation and properly formed words independently of the languages originally used to describe Esperanto. This norm diverges only minimally from the original ideal of "one letter, one sound"; that is, it accepts only minor allophonic variation.

Before Esperanto phonotactics became fixed, foreign words were adopted with spellings that violated the apparent intentions of Zamenhof and the norms that would develop later, such as poŭpo ('poop deck'), ŭato ('Watt'), and matĉo ('sports match'). Many of these coinages have proven to be unstable, and have either fallen out of use or been replaced with pronunciations more in keeping with the developing norms, such as pobo for poŭpo, vato for ŭato, and maĉo for matĉo. On the other hand, the word jida ('Yiddish'), which was also sometimes criticized on phonotactical grounds but had been used by Zamenhof, is well established.

The original Esperanto lexicon contains 23 consonants, including 4 affricates and one, /x/, which has become rare; and 11 vowels, 5 simple and 6 diphthongs. A few additional sounds in loan words, such as /ou̯/, are not stable.

The uncommon affricate /d͡z/ does not have a distinct letter in the orthography, but is written with the digraph ⟨dz⟩, as in edzo ('husband'). Not everyone agrees on its status as a phoneme; Wennergren considers it as a simple sequence of d + z. Consonantal /w/ is only found in onomatopoeia and in foreign names.

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