Phonological history of English close back vowels
This article discusses the history of these vowels in various dialects of English, focusing in particular on phonemic splits and mergers involving these sounds.
At some point, short /u/ developed into a lax, near-close near-back rounded vowel, /ʊ/, as found in words like put.
In a few of those words, notably blood and flood, the shortening happened early enough that the resulting /ʊ/ underwent the "foot–strut split" (see next section) and are now pronounced with /ʌ/.
For some speakers in Northern England, words ending in -ook that have undergone shortening to /ʊ/ elsewhere, such as book and cook, still have the long /uː/ vowel.
The absence of the foot–strut split is sometimes stigmatized,[6] and speakers of non-splitting accents may try to introduce it into their speech, which sometimes results in hypercorrection such as by pronouncing butcher /ˈbʌtʃər/.
[7] In Birmingham and the Black Country, the realisation of the FOOT and STRUT vowels is somewhat like a neutralisation between Northern and Southern dialects.
From a historical point of view, however, the name is inappropriate because the word foot did not have short /ʊ/ when the split happened, but it underwent shortening only later.
In modern standard varieties of English, such as Received Pronunciation (RP) and General American (GA), the FOOT vowel /ʊ/ is a fairly rare phoneme.
Otherwise, it is spelt -u- (but -o- after w-); such words include bull, bush, butcher, cushion, full, pudding, pull, push, puss, put, sugar, wolf, woman.
That can cause words such as hubbub (/ˈhʌbʌb/ in RP) to have two different vowels ([ˈhʌbəb]) even though both syllables contain the same phoneme in both merging and non-merging accents.
On the other hand, in Birmingham, Swansea and Miami, at least the non-final variant of the merged vowel is consistently realized as mid-central [ə], with no noticeable difference between the stressed and the unstressed allophones.
That largely matches an older canonical phonetic range of the IPA symbol ⟨ə⟩, which used to be described as covering a vast central area from near-close [ɪ̈] to near-open [ɐ].
[17] In contemporary Standard Southern British English, the final /ə/ is often mid [ə], rather than open [ɐ].
Even so, pairs of words belonging to the same lexical category exist as well such as append /əˈpɛnd/ vs up-end /ʌpˈɛnd/ and aneath /əˈniːθ/ vs uneath /ʌnˈiːθ/.
There also are words for which RP always used /ʌ/ in the unstressed syllable, such as pick-up /ˈpɪkʌp/, goosebumps /ˈɡuːsbʌmps/ or sawbuck /ˈsɔːbʌk/, that have merging accents use the same /ə/ as the second vowel of balance.
Again, this is not an internally motivated phonemic merger but the appliance of different languages' vowel systems to English lexical incidence.
[24][full citation needed] The quality of this final merged vowel is usually [ʉ~y~ʏ] in Scotland and Northern Ireland but [u] in Singapore.
In Geordie, the GOOSE vowel undergoes an allophonic split, with the monophthong [uː ~ ʉː] being used in morphologically-closed syllables (as in bruise [bɹuːz ~ bɹʉːz]) and the diphthong [ɵʊ] being used in morphologically-open syllables word-finally (as in brew [bɹɵʊ]) but also word-internally at the end of a morpheme (as in brews [bɹɵʊz]).
