Tswana first language interference on English vowels

Abstract

It has been indicated that the vowel system of Respectable South African English contains 12 primary vowels (Lass, 1990), whereas the Tswana vowel system consists of seven primary vowels (Kruger & Snyman, 1986). This can be the cause of under-differentiation (a form of negative language transfer) in the English vowels of Tswana speakers, which can lead to impairment of intelligibility. In order to test this hypothesis, perception tests were conducted, involving native speakers of Tswana and English. The perception of the vowels as pronounced by a Tswana reader would give an indication as to how they are pronounced. The focus of this study was on the vowels hi (it), N (miss), /ø:/ (nurse), Isel (trap) and hi (strut), which do not occur in the Tswana vowel system. Consequently, these vowels can be called "new" to the Tswana mother-tongue speaker. Certain "similar" vowels, i.e. Ii:l (fleece), hi (dress) and h:l (thought) were included in the research to test Flege's hypothesis that "equivalence classification prevents experienced L2 learners from producing similar L2 phones, but not new L2 phones, authentically" (Flege, 1987:47). Under-differentiation was, in fact, found to be a phenomenon in Tswana English, involving all of the above-mentioned vowels in one way or the other. The "new" vowels of the TL1 reader were not perceived accurately, but were confused with other vowels, whereas the "similar" vowels of the same speaker were perceived much more accurately (except in the case of Iel, which is probably due to the fact that this vowel is also used to represent Iæl and /ø:/, and therefore readily confused with these sounds). The results obtained seem to contradict Flege's hypothesis (Flege, 1987), although further research, e.g. in the light of the SDRH (Major & Kim, 1996) may clarify these apparent incongruities. Concerning the extent to which intelligibility is influenced or impaired, however, it was found to be impossible to draw any decisive conclusions from a study with such limited scope.