Spelling tone in Eastern Dan: a classroom experiment

I've just returned from Man, Côte d’Ivoire, where for the past three months I've been running a quantitative classroom experiment in the Eastern Dan language.


Eastern Dan is a South Mande language spoken in Côte d’Ivoire. It is unusual among African languages in that it has five level tones and six contours.

In the 1970s, researchers were faced with the unenviable challenge of developing a viable tone orthography for Eastern Dan while working with the limitations of manual typewriters. The solution they devised was to use word initial and word final punctuation marks, a radical departure from the conventional use of superscript accents.

The punctuation strategy was hailed as a local breakthrough at the time and was replicated in no less than fifteen Mande, Kru and Kwa languages in Côte d’Ivoire as well as being validated by national level authorities (ILA, 1979: 18-21). Although it has never been adopted beyond the borders of Côte d’Ivoire, it has nevertheless received some attention among writing systems researchers (Frieke-Kappers, 1991; Kutsch Lojenga, 1993: 13-14; 2014: 57-58; Roberts, 2013: 91).

Previous experimentation

In 2015, ten researchers working in five African countries ran a crosslinguistic quantitative classroom experiment. The aim was to test the efficiency of exhaustive tone marking in ten Niger-Congo languages including Eastern Dan. The Eastern Dan readers scored many more tonal errors and much lower on comprehension than any other language, whether or not tone was marked. These results are perhaps unsurprising since Eastern Dan is an outlier on three accounts:

  • It has a much higher functional load of tone than any of the other languages;
  • It has the only orthography in which tone is represented by punctuation rather than accents.
  • Its literacy primer is the only one that contains no dedicated tone lessons.

These considerations begged for a follow-up experiment investigating the use of punctuation to mark tone. More specifically, it is an opportunity to evaluate an ambitious spelling reform proposed by Valentin Vydrine (INALCO and LLACAN-CNRS). This orthography would represent tone by means of superscript accents instead of punctuation, eliminate over-representation of consonants and vowels, and replace umlauted vowels with special characters.

Experiment design

The experiment is taking place in the Focolari Centre in Man with 60 volunteers who will be learning how to read and write their language from scratch. It spans ten weeks and follows a 2 x 2 factorial design, permitting us to examine the effects of tone and segments independently of each other, and whether they interact. The participants will be assigned to four classes, each of which will be taught one spelling combination. All the classes will follow the same pedagogical materials except with respect to spelling. The participants will be tested on their acquired skills in dictation, oral reading and comprehension.

Anticipated impact

What little literature exists on tone orthography experimentation is dominated by designs that test the parameters of orthographic density and depth (Bernard et al., 2002; Bird, 1999; Mfonyam, 1989; Roberts et al., 2016). The proposed experiment will trace a different line of enquiry by testing the parameters of orthographic symbol and position.

The results will provide empirical data for those debating Eastern Dan spelling reform. It will also help any orthography developers worldwide who are working on languages with an exceptionally high functional load of tone.


This research project is supported by a public grant overseen by the French National Research Agency (ANR) as part of the “Investissements d’Avenir” program (reference: ANR-10-LABX-0083). It is part of a development project led by Valentin Vydrine (INALCO / LLACAN-CNRS) to test the tone orthography of Eastern Dan. I would like to thank Valentin for his invitation to collaborate with him and for his tireless help in the planning and execution of this experiment.


Bernard, Russell H., George N. Mbeh & W. Penn Handwerker (2002), Does marking tone make tone languages easier to read?, Human organisation 61:4.339-349.

Bird, Steven (1999), When marking tone reduces fluency: an orthography experiment in Cameroon, Language and Speech 42.83-115.

Frieke-Kappers, Claertje (1991), Tone orthography in African languages - a recommendation. Working papers in linguistics, 40. Amsterdam: Vrye Universiteit.

ILA (1979), Une orthographe pratique des langues ivoiriennes. Abidjan: Institut de linguistique appliquée, Université d'Abidjan.

Kutsch Lojenga, Constance (1993), The writing and reading of tone in Bantu languages, SIL Notes on Literacy 19.1–19.

Kutsch Lojenga, Constance (2014), Orthography and tone: a tone system typology with implications for orthography development in Developing orthographies for unwritten languages, ed. M. Cahill & K. Rice, 49-72. Dallas: SIL International.

Mfonyam, Joseph Ngwa (1989), Tone in Orthography: the Case of Bafut and Related Languages: Université de Yaoundé, Cameroun. Thèse d'état.

Roberts, David (2013), A tone orthography typology in Typology of Writing Systems, ed. S.R. Borgwaldt & T. Joyce, 85-111. Amsterdam: John Benjamins.

Roberts, David, Keith Snider & Steven Walter (2016), Neither deep nor shallow: testing the optimal orthographic depth for the representation of tone in Kabiye (Togo), Language and Speech 59:1.113–138.