Esperanto Phonology - Allophonic Variation

Allophonic Variation

With only five oral and no nasal or long vowels, Esperanto allows a fair amount of allophonic variation, though the distinction between /e/ and /ei̯/, and arguably /o/ and /ou̯/, is phonemic. Disregarding assimilation for the moment, the more noticeable allophony among the consonants is with /r/ and /v/. The /r/ may be pronounced as either an alveolar flap or an alveolar trill, in free variation but with the flap more common. The /v/ may be a labiodental fricative or a labiodental approximant, again in free variation, but with considered normative. Alveolar consonants t, d, n, l are acceptably either apical (as in English) or laminal (as in French, generally but incorrectly called "dental"). Postalveolars ĉ, ĝ, ŝ, ĵ may be palato-alveolar (semi-palatalized) as in English and French, or retroflex (non-palatalized) as in Polish, Russian, and Mandarin Chinese. H and ĥ may be voiced, especially between vowels. However, aspiration or incomplete voicing of consonants as in English or Mandarin is considered substandard, as are the English diphthongized "long" vowels for /i, e, u, o/.