English-language vowel changes before historic /l/

In the history of English phonology, there have been many diachronic sound changes affecting vowels, especially involving phonemic splits and mergers. A number of these changes are specific to vowels which occur before, especially in cases where the is at the end of a syllable (or is not followed by a vowel).

Historical diphthongization before /l/
Diphthongization occurred since Early Modern English in certain -al- and -ol- sequences before coronal or velar consonants, or at the end of a word or morpheme. In these sequences, became  and then, while  became  and then. Both of these merged with existing diphthongs: as in law and  as in throw.

At the end of a word or morpheme, this produced in all, ball, call, fall, gall, hall, mall, small, squall, stall, pall, tall, thrall and wall; in control, droll, extol, knoll, poll (meaning a survey of people,) roll, scroll, stroll, swollen, toll, and troll. The word shall did not follow this trend, and remains today.

Before coronal consonants, this produced in Alderney, alter, bald, balderdash, false, falter, halt, malt, palsy, salt, Wald and Walter;   in bold, cold, fold, gold, hold, molten, mould/mold, old, shoulder (earlier sholder), smolder, told, and wold (in the sense of "tract of land"). As with shall, the word shalt did not follow this trend, and remains today.

Before, this produced in balk, caulk/calk, chalk, Dundalk, falcon, stalk, talk and walk;  in folk, Polk, and yolk.

This L-vocalization established a pattern that would influence the spelling pronunciations of some relatively more recent loanwords like Balt, Malta, waltz, Yalta, and polder. It also influenced English spelling reform efforts, explaining the American English mold and molt vs. the traditional mould and moult.

Certain words of more recent origin or coining, however, do not have the change and retain short vowels, including Al, alcohol, bal, Cal, calcium, gal, Hal, mal-, pal, Sal, talc, Val, doll, Moll, and Poll (a nickname for a parrot.)

The Great Vowel Shift altered the pronunciation of the diphthongs, with becoming the monophthong, and  raising to.

Historical L-vocalization
In -alk and -olk words, the subsequently disappeared entirely in most accents (with the notable exception of Hiberno-English). This change caused to become, and  to become. Even outside Ireland, some of these words have more than one pronunciation that retains the sound, especially in American English where spelling pronunciations caused partial or full reversal of L-vocalization in a handful of cases:
 * caulk/calk can be or.
 * falcon can be, or.
 * yolk can be or .  yoke as  is only conditionally homophonous.

Words like fault and vault did not undergo L-vocalization, but rather L-restoration, having previously been L-vocalized independently in Old French and lacking the in Middle English, but having it restored by Early Modern English. The word falcon existed simultaneously as homonyms fauco(u)n and falcon in Middle English. The word moult/molt never originally had to begin with, instead deriving from Middle English mout and related etymologically to mutate; the  joined the word intrusively.

The loss of in words spelt with -alf, -alm, -alve and -olm did not involve L-vocalization in the same sense, but rather the elision of the consonant and usually the compensatory lengthening of the vowel.

Variation between /ɔːl/ and /ɒl/ before a consonant in salt and similar words
Some words such as salt, traditionally pronounced by most RP speakers with /ɔːl/ followed by a consonant, have alternative pronunciations with /ɒl/ that are used more frequently by younger British English speakers. This variation between /ɔːl/ and /ɒl/ occurs primarily before voiceless consonants, as in salt, false and alter; less commonly, /ɒl/ may also be used in words where the /l/ comes before a voiced consonant, as in bald, scald and cauldron. In Great Britain, this laxing before /l/ was traditionally associated with Northern England and Wales, but has in recent decades become more widespread, including among younger speakers of RP.

Modern L-vocalization
More extensive L-vocalization is a notable feature of certain dialects of English, including Cockney, Estuary English, New York English, New Zealand English, Pittsburgh and Philadelphia English, in which an sound occurring at the end of a word or before a consonant is pronounced as some sort of close back vocoid, e.g.,,  or. The resulting sound may not always be rounded. The precise phonetic quality varies. It can be heard occasionally in the dialect of the English East Midlands, where words ending in -old can be pronounced. KM Petyt (1985) noted this feature in the traditional dialect of West Yorkshire but said it has died out. However, in recent decades l-vocalization has been spreading outwards from London and the south east,  John C Wells argued that it is probable that it will become the standard pronunciation in England over the next one hundred years, an idea which Petyt criticised in a book review.

In Cockney, Estuary English and New Zealand English, l-vocalization can be accompanied by phonemic mergers of vowels before the vocalized, so that real, reel and rill, which are distinct in most dialects of English, are homophones as.

Graham Shorrocks noted extensive L-vocalisation in the dialect of Bolton, Greater Manchester and commented, "many, perhaps, associate such a quality more with Southern dialects, than with Lancashire/Greater Manchester."

In the accent of Bristol, syllabic can be vocalized to, resulting in pronunciations like  (for bottle). By hypercorrection, however, some words originally ending in were given an : the original name of the town was Bristow, but this has been altered by hypercorrection to Bristol.

African-American English (AAE) dialects may have L-vocalization as well. However, in these dialects, it may be omitted altogether (e.g. fool becomes . Some English speakers from San Francisco - particularly those of Asian ancestry - also vocalize or omit.

Salary–celery merger
The salary–celery merger is a conditioned merger of (as in bat) and  (as in bet) when they occur before, thus making salary and celery homophones. The merger is not well studied. It is referred to in various sociolinguistic publications, but usually only as a small section of the larger change undergone by vowels preceding in articles about l-vocalization.

This merger has been detected in the English spoken in New Zealand and in parts of the Australian state of Victoria, including the capital Melbourne. The merger is also found in the Norfuk dialect spoken on Norfolk Island. The salary-celery merger is also characteristic of Chicano English in Los Angeles and has been attested in the Chicano English of northern New Mexico and Albuquerque as well. is also often lowered before in El Paso, but not all speakers show a merger. In varieties with the merger, salary and celery are both pronounced.

The study presented by Cox and Palethorpe at a 2003 conference tested just one group of speakers from Victoria: 13 fifteen-year-old girls from a Catholic girls' school in Wangaratta. Their pronunciations were compared with those of school girl groups in the towns of Temora, Junee and Wagga Wagga in New South Wales. In the study conducted by Cox and Palethorpe, the group in Wangaratta exhibited the merger while speakers in Temora, Junee and Wagga Wagga did not.

Deborah Loakes from Melbourne University has suggested that the salary-celery merger is restricted to Melbourne and southern Victoria, not being found in northern border towns such as Albury-Wodonga or Mildura.

In the 2003 study Cox and Palethorpe note that the merger appears to only involve lowering of /e/ before /l/, with the reverse not occurring, stating that "There is no evidence in this data of raised /æ/ before /l/ as in 'Elbert' for 'Albert', a phenomenon that has been popularly suggested for Victorians."

investigates the effects of postvocalic on the preceding vowels in New Zealand English; her investigation covers all of the New Zealand English vowels and is not specifically tailored to studying mergers and neutralizations, but rather the broader change that occurs across the vowels. She has suggested that further research involving minimal pairs like telly and tally, celery and salary should be done before any firm conclusions are drawn.

A pilot study of the merger was done, which yielded perception and production data from a few New Zealand speakers. The results of the pilot survey suggested that although the merger was not found in the speech of all participants, those who produced a distinction between and  also accurately perceived a difference between them; those who merged  and  were less able to accurately perceive the distinction. The finding has been interesting to some linguists because it concurs with the recent understanding that losing a distinction between two sounds involves losing the ability to produce it as well as to perceive it (Gordon 2002). However, due to the very small number of people participating in the study the results are not conclusive.

Fill–feel merger
The fill–feel merger is a conditioned merger of the vowels and  before  that occurs in some accents. In Europe, it is commonly found in Estuary English. Otherwise it is typical of certain accents of American English. The heaviest concentration of the merger is found in, but not necessarily confined to, Southern American English: in North Carolina, eastern Tennessee, northern Alabama, Mississippi, northern and central Louisiana (but not New Orleans), and west-central Texas (Labov, Ash, and Boberg 2006: 69-73). This merger, like many other features of Southern American English, can also be found in AAE.

Fell–fail merger
The same two regions show a closely related merger, namely the fell–fail merger of and  before  that occurs in some varieties of Southern American English making fell and fail homophones. In addition to North Carolina and Texas, these mergers are found sporadically in other Southern states and in the Midwest and West.

Full–fool merger
The full–fool merger is a conditioned merger of and  before, making pairs like pull/pool and full/fool homophones. The main concentration of the pull–pool merger is in Western Pennsylvania English, centered around Pittsburgh. The merger is less consistently but still noticeably present in some speakers of surrounding Midland American English. The Atlas of North American English also reports this merger, or near-merger, scattered sporadically throughout Western American English, with particular prevalence in some speakers of urban Utahn, Californian, and New Mexican English. Accents with L-vocalization, such as New Zealand English, Estuary English and Cockney, may also have the full–fool merger in most cases, but when a suffix beginning with a vowel is appended, the distinction returns: Hence 'pull' and 'pool' are, but 'pulling' is whereas 'pooling' remains.

The fill–feel merger and full–fool merger are not unified in American English; they are found in different parts of the country, and very few people show both mergers.

Hull–hole merger
The hull–hole merger is a conditioned merger of and  before  occurring for some speakers of English English with l-vocalization. As a result, "hull" and "hole" are homophones as. The merger is also mentioned by Labov, Ash, and Boberg (2006: 72) as a merger before in North American English that might require further study. The latter merger can also involve or  before.

Gulf-golf merger
The gulf-golf merger is the merger of the diaphonemes and  before /lC/, where C denotes a consonant. It is attested in Australian English, in which it can co-occur with the Doll-dole merger. In Australian English the result of this 2-3 way merger is [ɔ], the vowel of.

Doll–dole merger
The doll–dole merger is a conditioned merger for many Southern England English, Australian English and New Zealand English speakers, of  and  before syllable-final (or non-prevocalic), resulting in homophony between pairs like doll and dole. The distinction between and  is maintained in derived forms containing prevocalic, such as dlling herself up  vs. dling it out, which means that the underlying vowel is recoverable if the  is morpheme-final, as in doll and dole. But when the is followed by a consonant within the same morpheme, as in solve, the distinction is not recoverable; this may be the cause, via hypercorrection, of pronunciations such as  for solve in place of RP.

Goat split
The goat split is a process that has affected London dialects, Australian English, and Estuary English. In the first phase of the split, the diphthong of goat developed an allophone  before "dark" (nonprevocalic). Thus goal no longer had the same vowel as goat ( vs. ). In the second phase, the diphthong spread to other forms of affected words. For example, the realization of rolling changed from to  on the model of roll. This led to the creation of a minimal pair for some speakers: wholly vs. holy  and thus to phonemicization of the split. The change from to  in derived forms is not fully consistent; for instance, in cockney, polar is pronounced with the  of goat even though it is derived from pole.

In broad Cockney, the phonetic difference between the two phonemes may be rather small and they may be distinguished by nothing more than the openness of the first element, so that goat is pronounced whereas goal is pronounced.

Goose split
Similar to the Goat split, the Goose vowel has developed contrasting phonetic outcomes before /l/ in some Southeastern English dialects, exhibited by the pair ruler (measuring instrument), pronounced with a fronter vowel that can be transcribed  or, and ruler ('one who rules'), pronounced with a backer vowel that can be transcribed ,  or. This contrast developed from an allophonic distribution where a back variant of the goose vowel is used before tautosyllabic /l/, as in rule, but a fronted variant closer to  is used elsewhere, as in ruler (instrument).

This distribution has become complicated by morphology in a way that is leading to a phonemic split in words with pre-vocalic /l/: those where the /l/ is stem-final are pronounced with the phonetically back vowel (as in ruler (monarch), a morphologically transparent derivative of rule), whereas those where the /l/ is stem-medial are pronounced with a fronted vowel  (as in ruler (measuring instrument), which is treated as an unanalyzable unit). The difference in vowel quality is presumably accompanied by a difference in the pronunciation of the following /l/ ([ɫ] after, [l] after ).

A similar backing change has occurred in many North American dialects, but this has remained allophonic. For example, in California English, the Goose vowel is realized as a back vowel in words such as school where it is followed by /l/, but is fronted in words where it is not followed by /l/, such as new.

Fool–fall merger
For some English speakers in the UK, the vowels of goose and thought may be merged before dark syllable-final /l/, which may be caused by the raising of the thought vowel to   or  in combination with the backing of the goose vowel before /l/ as part of the Goose split. This neutralization has been found to exist for clusters of speakers in the southern UK, especially for speakers from areas of the south coast and the Greater London area.

Vile–vial merger
The vile–vial merger is where the words in the vile set ending with (bile, file, guile, I'll, Kyle, Lyle, mile, Nile, pile, rile, smile, stile, style, tile, vile, while, wile) rhyme with words in the vial set ending with  (decrial, denial, dial, espial, Niall, phial, trial, vial, viol). This merger involves the dephonemicization of schwa that occurs after a vowel and before, causing the vowel- sequence to be pronounced as either one or two syllables.

This merger may also be encountered with other vowel rhymes too, including:
 * (jail, sale, tail, etc.) and (betrayal, Jael), usually skewing towards two syllables.
 * (coil, soil, etc.) and (loyal, royal), usually skewing towards two syllables.
 * (ceil, feel, steal, etc.) and (real), usually skewing towards two syllables.
 * (all, drawl, haul, etc.) and (withdrawal), usually skewing towards one syllable.
 * (bowl, coal, hole, roll, soul, etc.) and (Joel, Noel), usually skewing towards one syllable.
 * (cool, ghoul, mewl, rule, you'll, etc.) and (cruel, dual, duel, fuel, gruel, jewel), usually skewing towards one syllable.
 * (owl, scowl, etc.) and (bowel, dowel, Powell, towel, trowel, vowel), inconsistently skewing towards either one or two syllables.  Some words may wander across this boundary even in some non-merging accents, such as owl with, and bowel with.
 * In some rhotic accents, (girl, hurl, pearl, etc.) and  (referral), usually skewing towards two syllables.  This historically happened to the word squirrel, which was previously  (and still is in certain accents) but became one syllable  in General American today.  Some accents with one-syllable squirrel later broke it into two syllables again, as.
 * In some rhotic father–bother merged accents, (Carl, marl, etc.) and  (coral, moral), usually skewing towards two syllables.

For many speakers, the vowels in cake, meet, vote and moot can become centering diphthongs before, leading to pronunciations like , , and  for tail, teal, toll and tool.

Merger of non-prevocalic, , , with morpheme-internal
Cockney features a THOUGHT-split whereby the (the -- vowel) is pronounced differently depending on its position in the syllable structure:  in checked syllables and  in free syllables.

The L-vocalization of Cockney can leads to non-prevocalic /l/ being pronounced with a quality around, resulting in it being entirely absorbed by the preceding when it folllows a (by definition, morpheme-internal free syllable)  vowel in words such as bald, call and Paul, leading to homophonous pairs such as bald and board , called and cord , Paul's and pause.

Such homophones can only arise when the word without a historic /l/ also has the -- vowel in a morpheme-internal position, as in morpheme-final positions it will be pronounced as rather than, thus Paul's  and paws , bald  and bored  etc remain distinct.

The full-fool and fool-fall mergers, both of which are common in Cockney, can cause, to also merge with morpheme-internal , leading to homophonous pairs such as wolf and wharf  and cools and cause ; and 'pulls, pools, Paul's and pause all becoming homophonous as.

Non-prevocalic (as in bottle) can also merge with morpheme-interal, leading to musical being homophonous with music hall as. Cockney speakers usually regard both syllables of awful as rhyming:.

In the following list, the only homophonous pairs that are included are those involving a word with /l/ and a word without. As the merger is restricted to non-rhotic accents, morpheme-internal in the fifth columns is assumed to cover not only  but also  and.

Other mergers
Labov, Ash, and Boberg (2006:73) mention four mergers before that may be under way in some accents of North American English, and which require more study:
 * and (bull vs bowl)
 * and (hull vs hall)
 * and (bull vs hull) (effectively undoing the foot-strut split before )
 * and (hull vs bowl)