Meeussen’s rule is the name for a special case of tone reduction in Bantu languages. The tonal alternation it describes is the lowering in some contexts of the last tone of a pattern of two adjacent High tones (HH), resulting in the pattern HL. The phenomenon is named after its first observer, the Bantuist Achilles Emile Meeussen (1912–1978). In phonological terms, the phenomenon can be seen as a special case of the Obligatory Contour Principle.
Some illustrations of the phenomenon in Kirundi (examples adapted from Philippson 2003).
In verb forms
- na-rá-zi-báriira (I-PAST-them.CL10-to sew) ‘I was sewing them’ (them refers to a class 10 plural)
- na-rá-bariira (I-PAST-to sew) ‘I was sewing’
In the first sentence, both the tense marker 'rá' and the verb form 'báriira' (to sew) carry a high tone, signified by the acute accent. They are separated by the pronominal marker 'zi'. In the second sentence, the pronominal marker ‘zi’ is left out, resulting in two adjacent High tones. Due to the phenomenon described by Meeussen’s rule, the second High tone changes into a Low tone.
In noun forms
- bukéeye > umuɲábukéeye
- mwáaro > umuɲámwaaro
This examples show a way of deriving from place names nouns with the meaning ‘a person originating from’. In the first example, the place name bukéeye has a High tone on the second syllable. The junction with umuɲá (‘person from’) has no influence on this tone. In the second example, a place name with a High tone on the first syllable is used. Like above, the second High tone of the resulting pattern of two adjacent High tones is changed into a Low tone due to the phenomenon described by Meeussen’s rule.
- Goldsmith, J. (1984) ‘Meeussen’s rule’ in Aronoff, M. & Oehrle, R (eds.), Language sound structure, Cambridge, Mass., MIT.
- Sharman, J.C. & Meeussen, A.E. (1955) 'The representation of structural tones, with special reference to the tonal behaviour of the verb, in Bemba, Northern Rhodesia’. Africa, 25, 393-404.
- Philippson, Gérard (2003) Tone reduction vs. metrical attraction in the evolution of Eastern Bantu tone systems. Paris: INALCO. (online version)