Sotho Phonology - Historical Sound Changes

Historical Sound Changes

Probably the most radical sound innovation in the Sotho–Tswana languages is that the Proto-Bantu prenasalized consonants have become simple stops and affricates. Thus isiZulu words such as entabeni on the mountain, impuphu flour, ezinkulu the big ones, ukulanda to fetch, ukulamba to become hungry, ukuthenga to buy, etc. are cognates to Sesotho thabeng, phofo, tse kgolo, ho lata, ho lapa, and ho reka (with the same meanings).

This is further intensified by the law of nasalization and nasal homogeneity, making derived and imported words have syllabic nasals followed by homogeneous consonants, instead of prenasalized consonants.

Another important sound change in Sesotho which distinguishes it from almost all other Sotho–Tswana languages and dialects is the chain shift from /x/ and /k͡xʰ/ to /h/ and /x/ (the shift of /k͡xʰ/ to /x/ is not yet complete).

In certain respects, however, Sesotho is more conservative than other Sotho–Tswana languages. For example, the language still retains the difference in pronunciation between /ɬ/, /t͡ɬʰ/, and /tʰ/. Many other Sotho–Tswana languages have lost the fricative /ɬ/, and some Northern-Sotho languages, possibly influenced by Tshivenda, have also lost the lateral affricate and pronounce all three historical consonants as /tʰ/ (they have also lost the distinction between /t͡ɬ/ and /t/ — thus, for example, speakers of the Northern Sotho language commonly called Setlokwa call their language "Setokwa").

The existence of (lightly) ejective consonants (all unvoiced unaspirated stops) is very strange for a Bantu language and is thought to be due to Khoisan influence. These consonants occur in the Sotho–Tswana and Nguni languages (being over four times more common in Southern Africa than anywhere else in the world), and the ejective quality is strongest in isiXhosa, which has been greatly influenced by Khoisan phonology.

As with most other Bantu languages, almost all palatal and postalveolar consonants are due to some form of palatalization or other related phenomena which result from a (usually palatal) approximant or vowel being "absorbed" into another consonant (with a possible subsequent nasalization).

The Southern Bantu languages have lost the Bantu distinction between long and short vowels. In Sesotho the long vowels have simply been shortened without any other effects on the syllables; while sequences of two dissimilar vowels have usually resulted in the first vowel being "absorbed" into the preceding consonant, and causing changes such as labialization and palatalization.

As with most Southern African Bantu languages, the "composite" or "secondary" vowels *e and *o have become /ɛ/ and /e/, and /ɔ/ and /o/. These usually behave as two phonemes (conditioned by vowel harmony), although there are enough exceptions to justify the claim that they have become four separate phonemes in the Sotho–Tswana languages.

Additionally, the first-degree (or "superclose", "heavy") and second-degree vowels have not merged as in many other Bantu languages, resulting in a total of 9 phonemic vowels.

Almost uniquely among the Sotho–Tswana languages, Sesotho has adopted clicks. There is one place of articulation, alveolar, and three manners and phonations: tenuis, aspirated, and nasalized. These most probably came with loanwords from the Khoisan and Nguni languages, though they also exist in various words which don't exist in these languages and in various ideophones.

These clicks also appear in environments which are rare or non-existent in the Nguni and Khoisan languages, such as a syllabic nasal followed by a nasalized click (nnq in nnqane that other side), a syllabic nasal followed by a tenuis click (also written nq in senqanqane frog; this is not the same as the prenasalized radical click written nkq in the Nguni languages), and a syllabic nasal followed by an aspirated click (nqh in seqhenqha hunk).