Igbo phonology

## Vowels

Igbo is a tonal language. Tone varies by dialect but in most dialects there seems to be three register tones and three contour tones. The language's tone system was given by John Goldsmith as an example of autosegmental phenomena that go beyond the linear model of phonology laid out in *The Sound Pattern of English*. Igbo words may differ only in tone. An example is *ákwá* "cry", *àkwà* "bed", *àkwá* "egg", and *ákwà* "cloth". As tone is not normally written, these all appear as ⟨akwa⟩ in print.

In many cases, the two (or sometimes three) tones commonly used in Igbo dictionaries fail to represent how words actually sound in the spoken language . This indicates that Igbo may have many more tones than previously recognised. For example, the imperative form of the word *bia* "come" has a different tone to that used in statement *O bia* "he came". That imperative tone is also used in the second syllable of *abuo* "two". Another distinct tone appears in the second syllable of *asaa* "seven" and another in the second syllable of *aguu* "hunger".

The language features vowel harmony with two sets of oral vowels distinguished by pharyngeal cavity size described in terms of retracted tongue root (RTR). These vowels also occupy different places in vowel space: [i ɪ̙ e a u ʊ̙ o ɒ̙] (the last commonly transcribed [ɔ̙], in keeping with neighboring languages). For simplicity, phonemic transcriptions typically choose only one of these parameters to be distinctive, either RTR as in the chart at right and Igbo orthography (that is, as /i i̙ e a u u̙ o o̙/), or vowel space as in the alphabetic chart below (that is, as /i ɪ e a u ʊ o ɔ/). There are also nasal vowels.

Adjacent vowels usually undergo assimilation during speech. The sound of a preceding vowel, usually at the end of one word, merges in a rapid transition to the sound of the following vowel, particularly at the start of another word, giving the second vowel greater prominence in speech. Usually the first vowel (in the first word) is only slightly identifiable to listeners, usually undergoing centralisation. /kà ó mésjá/, for example, becomes /kòó mésjá/ "goodbye". An exception to this assimilation may be with words ending in /a/ such as /nà/ in /nà àlà/, "on the ground", which could be completely assimilated leaving /n/ in rapid speech, as in "nàlà" or "n'àlà". In other dialects however, the instance of /a/ such as in "nà" in /ọ́ nà èrí ńrí/, "he/she/it is eating", results in a long vowel, /ọ́ nèèrí ńrí/.

## Consonants

Igbo does not have a contrast among voiced occlusives (between voiced stops and nasals): the one precedes oral vowels, and the other nasal vowels. Only a limited number of consonants occur before nasal vowels, including /f, z, s/.

In some dialects, such as Enu-Onitsha Igbo, the doubly articulated /ɡ͡b/ and /k͡p/ are realized as a voiced/devoiced bilabial implosive. The approximant /ɹ/ is realized as an alveolar tap [ɾ] between vowels as in *árá*. The Enu-Onitsha Igbo dialect is very much similar to Enuani spoken among the Igbo-Anioma people in Delta State.

To illustrate the effect of phonological analysis, the following inventory of a typical Central dialect is taken from Clark (1990). Nasality has been analyzed as a feature of consonants, rather than vowels, avoiding the problem of why so few consonants occur before nasal vowels; [CjV] has also been analyzed as /CʲV/.

Syllables are of the form (C)V (optional consonant, vowel) or N (a syllabic nasal). CV is the most common syllable type. Every syllable bears a tone. Consonant clusters do not occur. The semivowels /j/ and /w/ can occur between consonant and vowel in some syllables. The semi-vowel in /CjV/ is analyzed as an underlying vowel "ị", so that *-bịa* is the phonemic form of *bjá* 'come'. On the other hand, "w" in /CwV/ is analyzed as an instance of labialization; so the phonemic form of the verb *-gwá* "tell" is /-ɡʷá/.

## References

1. ↑ Goldsmith, John A. 1976. *Autosegmental Phonology*. Ph.D. dissertation, Massachusetts Institute of Technology. Accessed at http://www.ai.mit.edu/projects/dm/theses/goldsmith76.pdf
2. ↑ Welmers, William Everett (1974). *African Language Structures*. University of California Press. pp. 41-42.
3. ↑ Mary Clark, 1990. *The Tonal System of Igbo*.