Vowels

Consonants

Note: /tʃ/ is found in loans, and the status of /ʔ/ as a phoneme is uncertain.

/r/ is typically realised as a tap when it is medial and a trill when it is in final position.

Fallon (2001, 2004) notes intervocalic lenition, such as /b/ → [β]; syncope, as in the name of the language, /bɨlín/ → [blín]; debuccalization with secondary articulation preserved, as in /dérekʷʼa/ → [dɛ́rɛʔʷa] 'mud for bricks'. Intriguingly, the ejectives have voiced allophones, which according to Fallon (2004) "provides an important empirical precedent" for one of the more criticized aspects of the glottalic theory of Indo-European. For example,

Geʽez abugida

A writing system for Bilen was first developed by missionaries who used the Geʽez abugida and the first text was published in 1882. Although the Geʽez script is usually used for Semitic languages, the phonemes of Bilen are very similar (7 vowels, labiovelar and ejective consonants). The script therefore requires only a slight modification (the addition of consonants for ŋ and ŋʷ) to make it suitable for Bilen. Some of the additional symbols required to write Bilen with this script are in the "Ethiopic Extended" Unicode range rather than the "Ethiopic" range.

Latin alphabet

In 1985 the Eritrean People's Liberation Front decided to use the Latin script for Bilen and all other non-Semitic languages in Eritrea. This was largely a political decision: the Geʽez script is associated with Christianity because of its liturgical use. The Latin alphabet is seen as being more neutral and secular. In 1993 the government set up a committee to standardize the Bilen language and the Latin-based orthography. "This overturned a 110-year tradition of writing Blin in Ethiopic script." (Fallon, Bilen Orthography ^[2])

As of 1997, the alphabetic order was:

e, u, i, a, é, o, b, c, d, f, g, h, j, k, l, m, n, p, q, r, s, t, v, w, x, y, z, ñ, ñw, th, ch, sh, kh, kw, khw, qw, gw.

Their values are similar to the IPA apart from the following: