Older age

This is the crucial factor accounting for the distribution of /a/ and /ɔ/. Simo Bobda (2000b: 188) observes that /a/ must have started to replace /ɔ/ during the last 40 years or so and is today associated mostly with the older generation. I agree that /a/ is the more modern GhE realization, but apparent time evidence in my recordings suggests that it must have started to replace /ɔ/ earlier than the 1960s. Apart from the few instances of RP /Λ/ > GhE /ε/ mentioned before, speakers born in the first decades of the 20^th century almost exclusively replace RP /Λ/ by /ɔ/, regardless of their linguistic background and educational attainment. Up to about 1930, this appears to have been the norm, but then /a/ began to replace earlier /ɔ/.

Exactly why and how this /ɔ > a/ replacement has been taking place is unclear, but there are indications that we are dealing with lexical diffusion here: although there is general /a ~ ɔ/ variation today, the occurrence of these phonemes is already strictly lexicalized in some words. The GhE pronunciation of e.g. some is always /sɔm/ , while come is /kam/, across the board and regardless of the sociolinguistic parameters of the speaker. Note that it is not the phonetic/phonological context that determines the occurrence of /ɔ/ in some and /a/ in come, since both end in a bilabial nasal and assimilation to the place of articulation of the preceding consonant would yield /a/ in some (alveolar /s/ imaginably favoring a front vowel) and /ɔ/ in come (velar /k/ triggering a back vowel). In fact, the pronunciation /kɔm/ come is frequently pointed out by Ghanaians as one of the characteristics of Nigerian English and one of the most salient differences between GhE and NigE. It therefore seems that, at least with some high-frequency words, the replacement of RP /Λ/ appears to be primarily lexically conditioned.

RP /ə/ in unstressed syllables is generally substituted by front and back vowels, depending mainly on orthography and the phonological context:

1. in post-tonic syllables involving <er, re, or, ur, ure> spellings, RP /ə/ is rendered as /a/ in open syllables and as /ε/ in closed syllables. Compare paper /pepa/ but papers /pepεs/, and in the accompanying conversation torture /tɔʧa/ but tortured /tɔʧεd/, doctor /dokta/ (both in speakers A and B) but investigators /ĩnvεstigetεs/ (speaker B). Post-tonic syllables of the type <our, ous, um, us> favor /ɔ/, as in honour, dangerous, column, or focus (contra Simo Bobda 2000b: 191–192, who predicts /a/ for <our>, and /ε/ for ), though sometimes /a/ can also be heard. /ɔ/ in open post-tonic syllables, e.g. rumour /rumɔ/ (speaker A), has been associated with the older generation (Simo Bobda 2000b: 191), but my recordings show that younger speakers use it just as often.
2. RP /-ən/ , tends to be realized as /-in/ rather than /-ən/. This affects -ed and -en participle forms, for example taken /tekin/ or spoken /spokin/, but also other words, like e.g. even /ivin/ (speaker B).
3. in other non-tonic syllables, RP /ə/ usually triggers spelling pronunciation. This is illustrated by speakers A and B's about /abaut/, official  and speaker C's submit /sabmit/. There are a few exceptions to this, though, such as alone /εlon/.
4. weak forms: Simo Bobda (2000b: 193) reports GhE /a/ for the indefinite article a, but this is decidedly a minority form in my recordings, /ε/ being by far the more common realization. The prevocalic form an is pronounced /an/. The distribution of the variants of the definite article the,  and , usually follows that in BrE: /dε/ is preconsonantal and /di/ precedes a vowel. There is some degree of variation, though, with the occasional preconsonantal /di/ (the forty women /di fɔti wumεn/) and /dε/ before vowels (the eight women /dε eⁱt wumεn/) – both speaker A. Vowels in other function words are generally modelled on the RP citation form, that is the RP schwa is replaced by spelling pronunciations, except in and, which is usually /εn(d)/ and only sometimes /an(d)/.