The aim of this study was to examine spoken Namibian English by investigating how multilingual Namibian speakers produce vowel durations in pre-lenis and pre-fortis positions, and how those vowel durations compare to British English vowel durations in the same words. In British English and most other English varieties, vowel duration is affected by the voicing of the following consonant, so that vowels preceding phonologically voiced consonants are longer (pre-lenis lengthening) and vowels preceding phonologically voiceless consonants are shorter (pre-fortis clipping). The production data was collected using orthographic stimuli that were monosyllabic English words with voiced and voiceless final consonants after the target vowels. The data were collected from 14 multilingual Namibian English speakers. The vowel durations produced by the speakers in pre-lenis and pre-fortis position were first compared to each other and then to those produced by nine British English speakers in an earlier study. The results showed that the pre-lenis vowels were clearly longer than the pre-fortis vowels, and there were no differences between Namibian and British English vowel durations in most of the tested words. The results offer new insights into the realization of vowel duration in pre-lenis and pre-fortis positions in Namibian English.

Using ten English adjectives, this study tests the hypothesis that the vowels in adjectives in predicative constructions are longer than those in attributive constructions in spoken conversation. The analyses considered a number of factors: occurrence before a pause, lexical adjective, vowel identity, probability given surrounding words, and others. Two sets of statistical techniques were used: a Mixed-effects model and the Random Forest Analysis based on Conditional Inference Trees (CIT). Both analyses showed strong effects of predicative vs. attributive constructions and individual lexical adjectives on vowel duration in the predicted direction, as well as effects of many of the phonological variables tested. The results showed that the longer duration in the predicative construction is not due to lengthening before a pause, though it is related to whether the adjective is internal or final in the predicative construction. Nor is the effect attributable solely to the probability of the occurrence of the adjective; rather construction type has to be taken into account. The two statistical techniques complement each other, with the Mixed-effects model showing very general trends over all the data, and the Random Forest / CIT analysis showing factors that affect only subsets of the data.