Phonological history of English close back vowels


Most dialects of modern English have two close back vowels: the near-close near-back rounded vowel found in words like foot, and the close back rounded vowel found in words like goose. The vowel, which historically was back, is often central as well. This article discusses the history of these vowels in various dialects of English, focusing in particular on phonemic splits and mergers involving these sounds.

Historical development

In the Old English vowel system, there was a pair of short and long close back vowels, and, both written . There was also a pair of back vowels of mid-height, and, written .
The same four vowels existed in the Middle English system. The short vowels were still spelt and, but long came to be spelt as, and as. Generally the Middle English vowels descended from the corresponding Old English ones, although there were certain alternative developments – see Phonological history of Old English#Changes leading up to Middle and Modern English.
Due to Middle English open syllable lengthening, short was mostly lengthened to in open syllables; this development can be seen in words like nose. In the Great Vowel Shift, ME long ended up being raised to, in words like moon; ME long was diphthongized, becoming the present-day, as in mouse; and the of nose was raised and later diphthongized, leading to present-day.
At some point, short developed into a lax, near-close near-back rounded vowel,, as found in words like put. According to Roger Lass, this laxing occurred in the 17th century, but other linguists have suggested that it may have taken place much earlier. The short remaining in words like lot has also been lowered, and unrounded in some accents.

Shortening of to

In a handful of words, including some very common ones, the vowel was shortened to. In a few of these words, notably blood and flood, this shortening happened early enough that the resulting underwent the "foot–strut split" and are now pronounced with. Other words that underwent shortening later consistently have, such as good, book, and wool. Still other words, such as roof, hoof, and root are in the process of the shift today, with some speakers preferring and others preferring in such words; for example in Texas. For some speakers in Northern England, words ending in -ook such as book, cook still have the long vowel.

''Foot–strut'' split

The foot–strut split is the split of Middle English short into two distinct phonemes and . The split occurs in most varieties of English, the most notable exceptions being the majority of Northern England and the English Midlands, and some varieties of Hiberno-English. In Welsh English, the split is also absent in parts of North Wales, under influence from Merseyside and Cheshire accents, and south Pembrokeshire, an area where English replaced Welsh long before this occurred in the rest of Wales.
The origin of the split is the unrounding of in Early Modern English, resulting in the phoneme. In general, unrounding to did not occur if was preceded by a labial consonant and followed by,, or, leaving the modern. Because of the inconsistency of the split, the words put and putt became a minimal pair, distinguished as and. The first clear description of the split dates from 1644.
In non-splitting accents, cut and put rhyme, putt and put are homophonous as, and pudding and budding rhyme. However luck and look may not necessarily be homophones; many accents in the area concerned have look as, with the vowel of goose. In the Coventry area, Schwas are often hyper-corrected to, such as for 'button'.
The absence of this split is a less common feature of educated Northern English speech than the absence of the trap–bath split. The absence of the foot–strut split is sometimes stigmatized, and speakers of non-splitting accents may try to introduce it into their speech, sometimes resulting in hypercorrections such as pronouncing butcher.
The name "foot–strut split" refers to the lexical sets introduced by, and identifies the vowel phonemes in the words. From a historical point of view, this name is inappropriate because the word foot did not have short at the time the split happened, but underwent shortening at a later time.
In modern standard varieties of English, e.g. Received Pronunciation and General American, the spelling is a reasonably good guide to whether a word is in the FOOT or STRUT lexical sets. The spellings o and u nearly always indicate the STRUT set, while the spellings oo and ould usually indicate the FOOT set. The spellings of some words changed in accordance with this pattern: e.g. wull became wool and wud became wood. In some recent loan words such as Muslim both pronunciations are found.

''Strut–comma'' merger

The strut–comma merger or the strut–schwa merger is a merger of with which occurs in Welsh English and some higher-prestige Northern England English. It is also usual in General American, and it causes minimal pairs such as unorthodoxy and an orthodoxy to be merged. The phonetic quality of the merged vowel depends on the accent. For instance, in merging General American accents is the stressed variant, the word-final one is and elsewhere the vowel surfaces as or even . This can cause words such as hubbub to have two different vowels, even though both syllables contain the same phoneme in both merging and non-merging accents. On the other hand, in Birmingham, Miami and Swansea at least the non-final variant of the merged vowel is consistently realized as mid central, with no noticeable difference between the stressed and unstressed allophones.
The merged vowel is typically written with, regardless of its phonetic realization. To a large extent, this matches an older canonical phonetic range of the IPA symbol, which used to be described as covering a vast central area from near-close to near-open.
Because of the unstressed nature of the merger occurs only in unstressed syllables. Word-finally, the two vowels do not contrast in any accent of English and the vowel which occurs in that position approaches , though there is some dialectal variation, with varieties such as broad Cockney using strikingly more open variants than other dialects. It is usually identified as belonging to the phoneme, even in accents without the merger, but native speakers may perceive the phonemic makeup of words such as comma to be rather than. This open variety of occurs even in Northern English dialects which have not undergone the foot–strut split, though in Geordie it can be generalized to other positions so that not only comma but also commas can be pronounced with in the second syllable, which is rare in other accents. In contemporary General British the final is often mid, rather than open.
All speakers of General American neutralize, and before, which results in an r-colored vowel. GA lacks a truly contrastive phoneme and the symbol is used only to facilitate comparisons with other accents. See hurry–furry merger for more information.
Some other minimal pairs apart from unorthodoxyan orthodoxy include unequal vs. an equal as well as a large untidy room vs. a large and tidy room. However, there are few minimal pairs like this and using them as such has been criticized by scholars such as Geoff Lindsey because the members of such minimal pairs are structurally different. There also are words which in RP always have in the unstressed syllable, such as pick-up or sawbuck which in merging accents have the same as the second vowel of balance. In RP, there is a consistent difference in vowel height; the unstressed vowel in the first two words is a near-open , whereas in balance it is a mid.
IPA
a large untidy rooma large and tidy room
unequalan equal
unorthodoxyan orthodoxy

Development of the sequence /juː/

Earlier Middle English distinguished the close front rounded vowel and the diphthongs , and .
By the time of Late Middle English,,, and had merged as. In Early Modern English, merged into as well.
This has remained as such in some Welsh, some northern English, and a rare few American accents, so that, in a variety of Welsh English, threw is distinct from through. In the majority of accents, however, the falling diphthong turned into a rising diphthong, which became the sequence. This change had taken place in London by the end of the 17th century. Depending on the preceding consonant and on the dialect, this either remained as or developed into by the processes of yod-dropping or yod-coalescence. Hence the present-day standard English pronunciations of duke , new, few and rude.

''Foot–goose'' merger

The foot–goose merger is a phenomenon that occurs in Scottish English, Ulster varieties of Hiberno-English, Malaysian English and Singapore English, where the vowels and are merged. As a result, pairs like look/Luke are homophones and good/food and foot/boot rhyme. The quality of the merged vowel is usually or in Scottish English and in Singapore English. The use of the same vowel in "foot" and "goose" in these dialects is not due to phonemic merger, but the appliance of different languages' vowel system to the English lexical incidence. The full–fool merger is a conditioned merger of the same two vowels before, making pairs like pull/pool and full/fool homophones.

Other changes

In Geordie, the vowel undergoes an allophonic split, with the monophthong being used in morphologically closed syllables and the diphthong being used in morphologically open syllables, not only at the very end of a word, but also word-internally at the end of a morpheme.
Many other dialects of English diphthongize, but in most of them the diphthongal realization is in a more or less free variation with the monophthong.
Compare the identical development of the close front vowel.
The change of to is a process that occurs in many varieties of British English where bisyllabic becomes the diphthong in certain words. As a result, "ruin" is pronounced as monosyllabic and "fluid" is pronounced.