When we want to express how a certain noun or noun phrase is related to another noun or noun phrase in a sentence, perhaps even with the involvement of an action, we use different methods to express such a relationship in our languages. Some languages do not modify the arguments, instead using a more rigid word order and pre- or postpositions to reflect these relationships. Other languages may modify these nouns, through this thing called grammatical case inflections. Such modifications usually involve the use of case suffixes, while a minority have some sort of case prefixes. However, I want to talk about a special way of such an expression, something that we only find in some languages in Africa.

We are generally familiar with the concept of tone. Some languages distinguish between distinct words by tone, while other languages use tone to convey some sort of speech rhythm or adding something to the meaning of the sentence. But phonemic tone usually only covers the languages that make use of tone to distinguish between different lexical terms (like ‘horse’ and ‘mother’), and even grammatical meaning.

Synthesising these introductions together, we realise that there are some languages in the world that use tone to reflect grammatical case. Here, differences in tonal patterns could distinguish between a particular grammatical case from another, such as high-low tone pattern differences in languages such as Maasai, a Nilotic language spoken in Kenya and Tanzania.

As aforementioned, tonal case systems are predominantly found in the languages of Africa, with most of them belonging to the vast Nilo-Saharan language family, spoken in as far north as Southern Libya, as far south as Tanzania, and as far west as Niger. Some of the most famous languages belonging to this family include the Maasai language spoken by the Maasai people, and the Dinka and Nuer languages spoken in South Sudan. In addition to the Nilo-Saharan languages, there is also one proposed Niger-Congo language that has case tones. According to the World Atlas of Language Structures, this brings the total number of languages that have been proposed to have some system of case tone to 5. As this atlas uses a sample of languages, there could be more languages that mark grammatical case using tone, although it seems that tonal case systems are generally very rare.

To better illustrate how tonal case systems work, we should take a look at the languages that use them. We will start with the Maasai language, also known as the Maa language, or ɔl Maa. There are four tones in the Maa language, which are the rising, level, low, and falling tones. Using the /a/ sound as an example, these tones are written as á, a, à, and â respectively.

Within Maa nouns, there are largely 4 different patterns in which nouns may decline by grammatical case. Maa only uses 2 grammatical cases, the nominative and the accusative, while locatives are usually expressed using a preposition with the accusative case. There are 4 different patterns where nouns may decline, which includes one where there is basically no case marking at all. The first one has the nominative in all low tones and the last syllable being of high tone. This pattern becomes a low tone syllable followed by all high tones in the accusative. The second one features the nominative having a high tone in the first syllable, while the accusative is marked by a high tone in the second syllable. The third pattern features 2 high tone syllables in the nominative, and one high tone syllable in the accusative. And lastly, there is the fourth pattern, that do not change by grammatical case. Hyman’s 2016 publication shows some examples, listed here below. Note that Maa also uses a system of noun classes that are shown as prefixes, marked as en- or ol-.

Class	English word	Nominative	Accusative
1 (e.g.) LLLH -> LHHH	head	è-lʊ̀kʊ̀nyá	è-lʊ́kʊ́nyá
2 (e.g.) HLL -> LHL	rat	èn-dérònì	èn-dèrónì
3 (e.g.) HHL -> HLL	buffalo	òl-ósówùàn	òl-ósòwùàn
4 – no change	fish	ò-sínkìrrî	ò-sínkìrrî

Our next example takes us to the highlands of Western Kenya, in which the Naandi language is predominantly spoken. Like Maasai, Naandi is also a Nilo-Saharan language, but it exhibits 5 tones instead of 4. These are the low level, high level, high rising, high falling, and the low falling tones. There are additional tonological processes described in Creider and Creider’s 1989 publication, A Grammar of Nandi, which can deviate from the 5 tones described earlier, and so I would recommend giving that publication a read to learn more.

While there is evidence of suffix and prefix case marking for the locative, instrumental, and the dative cases, Naandi does exhibit some form of case tone marking for the nominative and oblique cases. For instance, the primary forms of pronouns have a low level tone in the last syllable in the nominative, but this changes to the high falling tone in the oblique. In the secondary forms of the pronouns, the first syllable is a low level tone in the nominative, but this becomes a high level tone in the oblique. Tonal cases also apply for nouns and adjectives, but the system for adjectives is generally more elaborate, with tonal contour differences used to express things like “tasty fruit” and “it is tasty”. Additionally, there are more regular rules assigned for case marking in Naandi adjectives, which depend on the segmental shapes of the adjectives.

The last example we will be looking at is part of the Niger-Congo language family. Mainly spoken in Mali and Burkina Faso, the Jamsay language, or Jamsai Dogon or Dyamsay tegu language, distinguishes a total of 5 tones – the high (H), the low (L), the rising (LH), the falling (HL), and the bell-shaped (LHL) tones. Grammatical tone here takes place via two ways — by using a system of tone overlays on the word stem, or by using tone grafting, that is, by altering the tone at the end of the word stem. There are also other tonological processes in play, but this system of grammatical tone is perhaps the most notable feature of interest here.

While possessor-possession relationships are generally expressed using suffixes, the main case in which a tonal case system is used is the locative case. For nouns, this takes places via tonal grafting, which takes place as a low tone grafted at the end of the word stem. And so, for the word ‘pond’, búró, this becomes búrò in the locative. And for monosyllabic nouns like ‘mouth’, ká:, this becomes a falling syllable as the low tone is grafted onto it, as kâ:. Note that this may also take place for words with more syllables as well. However, the locative case may also be constructed by other means as well, such as a postposition. These postpositions are also used in the construction of a dative and instrumental cases.

And so, this has been an introduction to a rather unusual way of expressing grammatical case in the world’s languages. As we have seen in these examples, there are generally few grammatical cases in these systems, and they may be complemented with other methods of expressing other grammatical functions (location etc.) such as post- and prepositions. These languages included in the World Atlas of Language Structures sample are still thriving today, although it is unclear if there could be more such languages that can be argued as having some form of tonal case system. These languages definitely deserve a deeper look into, and I will link some published material in Further Reading below.

Further Reading

Creider, C. A. & Creider, J. T. (1989) ‘A grammar of Nandi’, Nilo-Saharan Linguistic Analyses and Documentation, 4.

Hyman, L. H. (2016) ‘Lexical vs grammatical tone: Sorting out the differences’, 5th International Symposium on Tonal Aspects of Languages , pp. 6-11.

Kohnen, B. (1933) ‘Shilluk grammar with a little English-Shilluk dictionary’, Verona: Missioni Africane.

Miller, C. L. & Gilley, L. G. (2001) ‘Evidence for ergativity in Shilluk’, Journal of African Languages and Linguistics, 22(1), pp. 33-68.

Weiss, D. (2009) ‘Phonologie et morphosyntaxe du Maba’, Linguistique, Lyon, France.