View source for Social:Phonological history of English open back vowels

{{Short description|Sound change}}
The phonology of the open back vowels of the [[Social:English language|English language]] has undergone changes both overall and with regional variations, through [[Social:Old English|Old]] and [[Social:Middle English|Middle English]] to the present. The sounds heard in modern English were significantly influenced by the Great Vowel Shift, as well as more recent developments in some dialects such as the ''cot–caught'' merger.

==Overview==

===Old and Middle English===
In the Old English vowel system, the vowels in the open back area were unrounded: {{IPA|/ɑ/, /ɑː/}}. There were also rounded back vowels of mid-height: {{IPA|/o/, /oː/}}. The corresponding spellings were {{angbr|a}} and {{angbr|o}}, with the length distinctions not normally marked; in modern editions of Old English texts, the long vowels are often written {{angbr|ā}}, {{angbr|ō}}.

As the Old English (OE) system developed into that of Middle English (ME), the OE short vowel {{IPA|/ɑ/}} merged with the fronted {{IPA|/æ/|cat=no}} to become a more central ME {{IPA|/a/}}. Meanwhile, the OE long vowel {{IPA|/ɑː/}} was rounded and raised to ME {{IPA|/ɔː/}}. OE short {{IPA|/o/}} remained relatively unchanged, becoming a short ME vowel regarded as {{IPA|/o/ or /ɔ/}}, while OE long {{IPA|/oː/}} became ME {{IPA|/oː/}} (a higher vowel than {{IPA|/ɔː/}}). Alternative developments were also possible; see English historical vowel correspondences for details.

Later, ME open syllable lengthening caused the short vowel {{IPA|/o/}} to be normally changed to {{IPA|/ɔː/}} in open syllables. Remaining instances of the short vowel {{IPA|/o/}} also tended to become lower. Hence in Late Middle English (around 1400) the following open back vowels were present, distinguished by length:{{sfnp|Barber|1997|pp=108, 111}}
* {{IPA|/ɔ/}}, spelt {{angbr|o}}, as in ''dog'', ''god''
* {{IPA|/ɔː/}}, often spelt {{angbr|oa}}, or {{angbr|o}} before consonant+vowel or certain consonant pairs, as in ''boat'', ''whole'', ''old''

===16th-century changes===
By 1600, the following changes had occurred:
* The long vowel {{IPA|/ɔː/}} of ''boat'' had been raised to {{IPA|/oː/}} as a result of the Great Vowel Shift.
* The diphthong {{IPA|/aw/}} found in words such as ''cause'', ''law'', ''all'', ''salt'', ''psalm'', ''half'', ''change'', ''chamber'', ''dance'' had become an open back monophthong {{IPA|/ɔː/}} or {{IPA|/ɑː/}}.
* At this time, the short {{IPA|/ɔ/}} in ''dog'' was lowered to {{IPA|/ɒ/}}

There were thus two open back monophthongs: 
* {{IPA|/ɒ/}} as in ''lot''
* {{IPA|/ɔː/}} or {{IPA|/ɑː/}} as in ''cause''

and one open back diphthong: 
* {{IPA|/ɔw/}} as in ''low''

===17th-century changes===
By 1700, the following further developments had taken place:
* The diphthong {{IPA|/ɔw/}} of ''soul''  was raised to {{IPA|/ow/}}, and then monophthongized to {{IPA|/oː/}}, merging with ''boat'' (see ''toe–tow'' merger). Before {{IPA|/r/}}, this vowel further merged with {{IPA|/ɔː/}} due to the horse–hoarse merger except in some varieties, as currently seen in Irish English, Scottish English and African American Vernacular English.
* Short {{IPA|/wa/}} was retracted and rounded to {{IPA|/wɒ/}}. The shift was suppressed before a velar consonant, as in ''quack'', ''twang'', ''wag'', ''wax'', and also was suppressed by analogy in ''swam'' (the irregular past tense of ''swim''). The change of {{IPA|/wa/}} to {{IPA|/wɒ/}} did not occur in Mid-Ulster English.
* {{IPA|/ɒ/}} had begun to partake in lengthening and raising before a nonprevocalic voiceless fricative or /r/. That resulted in words like ''broth'', ''cost'' and ''off'' having {{IPA|/ɒː/}} instead of {{IPA|/ɒ/}}, and was the start of the {{sc2|LOT–CLOTH}} split (see further below).
* In words such as ''change'' and ''chamber'', the pronunciation {{IPA|/ɔː/}} was gradually replaced in the standard language by a variant with {{IPA|/eː/}}, derived from Middle English {{IPA|/aː/}}. That explains the contemporary pronunciation of these words with {{IPA|/eɪ/}}.
* However, when {{IPA|/ɔː/}} preceded {{IPA|/f/}}, as in ''laugh'' and ''half'', {{IPA|/ɔː/}} was shifted to {{IPA|/æ/}} instead, derived from Middle English {{IPA|/a/}}.
* An unrounded back vowel {{IPA|/ɑː/|cat=no}} developed, found in certain classes of words that had previously had {{IPA|/a/}}, like ''start'', ''father'' and ''palm''.

That left the standard form of the language with four open back vowels:
* {{IPA|/ɒ/}} in ''lot'' and ''want''.
*{{IPA|/ɒː/}} in ''cloth'' and ''cost''.
*{{IPA|/ɑː/}} in ''start'', ''father'' and ''palm''.
* {{IPA|/ɔː/}} in ''tor'', ''cause'', and ''corn''.

===Later changes===
From the 18th century on, the following changes have occurred:
* The three-way distinction between {{IPA|/ɒ/}}, {{IPA|/ɒː/}}, and {{IPA|/ɔː/}} was simplified in one of two ways:
** In [[Social:General American|General American]] and old-fashioned RP, {{IPA|/ɒː/}} was raised to {{IPA|/ɔː/}}, merging with the vowel in {{sc2|THOUGHT}} (the ''cloth-thought'' merger).
** In many accents of England, the lengthening of the {{sc2|CLOTH}} set was undone, restoring the short pronunciation {{IPA|/ɒ/}}. This became standard RP by the mid-20th century.
* In General American, the ''lot'' vowel has become unrounded and merged into {{IPA|/ɑ/}} (the ''father–bother'' merger).

This leaves RP with three back vowels:
* {{IPA|/ɒ/}} in ''lot'', ''want'', ''cloth'', and ''cost''.
* {{IPA|/ɔː/}} in ''tor'', ''cause'', and ''corn''.
* {{IPA|/ɑː/}} in ''start'', ''father'', and ''palm''.

and General American with two:
* {{IPA|/ɑ/}} in ''lot'', ''want'', ''start'', ''father'', and ''palm''.
* {{IPA|/ɔ/}} in ''tor'', ''cause'', ''corn'', ''cloth'' and ''cost''.

== Unrounded {{sc2|LOT}} ==
In a few varieties of English, the vowel in ''lot'' is unrounded, pronounced toward [{{IPA|ɑ}}].  This is found in the following dialects:
* Most of Irish English
* Much of the Caribbean
* Norwich
* The West Country and the West Midlands of England
* Most of North American English
** Excluding New England English, where it is typically raised toward {{IPA|/ɔ/}}, merging with the vowel in ''thought''.

There's also evidence for it in South East England as early as the late 16th century and as late as the 19th century.<ref>{{Cite journal |last=Mazarin |first=André |date=2020-01-01 |title=The developmental progression of English vowel systems, 1500–1800: Evidence from grammarians |url=https://www.sciencedirect.com/science/article/pii/S2215039020300011 |journal=Ampersand |language=en |volume=7 |pages=100058 |doi=10.1016/j.amper.2020.100058 |issn=2215-0390|doi-access=free }}</ref><ref>{{Cite journal |last=Trudgill |first=Peter |last2=Gordon |first2=Elizabeth |last3=Lewis |first3=Gillian |last4=Maclagan |first4=Margaret |date=2000 |title=Determinism in new-dialect formation and the genesis of New Zealand English |url=https://www.academia.edu/25185542/Determinism_in_new_dialect_formation_and_the_genesis_of_New_Zealand_English |journal=Journal of Linguistics |volume=36 |issue=2 |pages=299 |issn=0022-2267}}</ref>

Linguists disagree as to whether the unrounding of the ''lot'' vowel occurred independently in North America (probably occurring around the end of the 17th century) or was imported from certain types of speech current in Britain at that time.{{citation needed|date=December 2019}}

In such accents outside of North America, ''lot'' typically is pronounced as {{IPA|[lɑt]}},{{sfnp|Wells|1982|pp=245, 339–40, 419}} therefore being kept distinct from the vowel in ''palm'', pronounced {{IPA|[pɑːm]}} or {{IPA|[paːm]}}. However, the major exception to this is North American English, where the vowel is lengthened to merge with the vowel in ''palm'', as described below.  This merger is called the '''{{sc2|LOT–PALM}}''' merger or more commonly the ''father–bother'' merger.  (See further below.)

=== ''Father–bother'' merger ===
The '''''father–bother'' merger''' is a phonemic merger of the lexical sets {{sc2|LOT}} and {{sc2|PALM}}. It represents unrounded ''lot'', as detailed above, taken a step further.  On top of being unrounded, the length distinction between the vowel in ''lot'' and ''bother'' and the vowel in ''palm'' and ''father'' is lost, so that the two groups merge. This causes ''father'' and ''bother'' to become rhymes.

This occurs in the great majority of North American accents; of the North American dialects that have unrounded ''lot'', the only notable exception to the merger is New York City English, where the opposition with the {{IPA|[ɑ]}}-type vowel is somewhat tenuous.{{sfnp|Wells|1982|pp=136–37, 203–6, 234, 245–47, 339–40, 400, 419, 443, 576}}{{sfnp|Labov|Ash|Boberg|2006|p=171}}

Examples of possible [[Philosophy:Homophone|homophone]]s resulting from the merger include ''Khan'' and ''con'' ({{IPA|/kɑn/}}) as well as ''Saab'' and ''sob'' ({{IPA|/sɑb/}}).{{sfnp|Labov|Ash|Boberg|2006|p=169}}

While the accents in northeastern New England, such as the Boston accent, also remain unmerged, ''lot'' remains rounded and merges instead with ''cloth'' and ''thought''.{{sfnp|Wells|1982|pp=136–37, 203–6, 234, 245–47, 339–40, 400, 419, 443, 576}}{{sfnp|Labov|Ash|Boberg|2006|p=171}}

{| class="wikitable sortable mw-collapsible mw-collapsed"
|+ class="nowrap" | Homophonous pairs
! {{IPA|/ɑ:/}}
! {{IPA|/ɒ/ or /ɔ/{{efn|only homophonous with the cot-caught merger}} 
! IPA (using {{angbr IPA|ɑ}} for the merged vowel)
! Notes
|-
| ah || awe || {{IPA|ˈɑ}} || with the cot-caught merger
|-
| balm || bomb || {{IPA|ˈbɑm}} || when the <l> in balm is unsounded
|-
| [[Place:Bali|Bali]] || bolly<ref>{{cite web|url=https://www.merriam-webster.com/dictionary/bolly|publisher=Merriam-Webster|title=Bolly Definition & Meaning|access-date=2022-12-09}}</ref> || {{IPA|ˈbɑli}}
|
|-
| [[Physics:Thai baht|baht]] || bot || {{IPA|ˈbɑt}}
|
|-
| baht || bought || {{IPA|ˈbɑt}} || with the cot-caught merger
|-
| Dalí || dolly || {{IPA|ˈdɑli}}
|
|-
| [[Religion:Hajj|Hajj]] || Hodge || {{IPA|ˈhɑdʒ}}
|
|-
| Khan || con || {{IPA|ˈkɑn}}
|
|-
| la<ref>{{cite web|url=https://dictionary.cambridge.org/dictionary/english/la|publisher=Cambridge Dictionary|title=LA English meaning|access-date=2022-12-27}}</ref> || law || {{IPA|ˈlɑ}} || with the cot-caught merger
|-
| lager || logger || {{IPA|ˈlɑgər}} || 
|-
| Mali || Molly || {{IPA|ˈmɑli}}
|
|-
| pa || paw || {{IPA|ˈpɑ}} || with the cot-caught merger
|-
| palm || pom || {{IPA|ˈpɑm}} || when the <l> in palm is unsounded
|-
| [[Place:Prague|Prague]] || prog<ref>{{cite web|url=https://www.merriam-webster.com/dictionary/prog|publisher=Merriam-Webster|title=Prog Definition & Meaning|access-date=2022-12-27}}</ref> || {{IPA|ˈprɑg}}
|
|-
| Raab || rob || {{IPA|ˈrɑb}}
|
|-
| Saab || sob || {{IPA|ˈsɑb}}
|
|-
| Shah ||  Shaw || {{IPA|ˈʃɑ}} || with the cot-caught merger
|-
| Siân ||  Sean, Shaun, Shawn || {{IPA|ˈʃɑn}} || with the cot-caught merger
|-
| Siân || shone || {{IPA|ˈʃɑn}}
|
|-
| Stalin ||  stalling || {{IPA|ˈstɑlɪn}} || with the cot-caught merger and G-dropping.
|}

== {{sc2|LOT–CLOTH}} split ==
The '''{{sc2|LOT–CLOTH}} split''' is the result of a late 17th-century sound change that lengthened {{IPA|/ɒ/}} to {{IPA|[ɒː]}} before voiceless fricatives, and also before {{IPA|/n/}} in the words ''gone'' and sometimes ''on''. It was ultimately raised and merged with {{IPA|/ɔː/}} of words like ''thought'', although in some accents that vowel is actually open {{IPA|[ɒː]}}. This means that {{sc2|CLOTH}} is not a separate vowel; rather, it means "either {{sc2|LOT}} or {{sc2|THOUGHT}}, depending on the accent". The sound change is most consistent in the last syllable of a word, and much less so elsewhere (see below). Some words that entered the language later, especially when used more in writing than speech, are exempt from the lengthening, e.g. ''joss'' and ''Goth'' with the short vowel. Similar changes took place in words with {{angbr|a}}; see ''trap–bath'' split and /æ/-tensing.

The cot–caught merger, discussed below, has removed the distinction in some dialects.

As a result of the lengthening and raising, in the above-mentioned accents ''cross'' rhymes with ''sauce'', and ''soft'' and ''cloth'' also have the vowel {{IPA|/ɔː/}}. Accents affected by this change include American English accents that lack the cot-caught merger and, originally, [[Social:Received Pronunciation|RP]], although today words of this group almost always have short {{IPA|/ɒ/}} in RP.  The split still exists in some older RP speakers.

The lengthening and raising generally happened before the fricatives {{IPA|/f/}}, {{IPA|/θ/}} and {{IPA|/s/}}. In American English the raising was extended to the environment before velars {{IPA|/ŋ/}} and {{IPA|/ɡ/}}, and sometimes before {{IPA|/k/}} as well, giving pronunciations like {{IPA|/lɔŋ/}} for ''long'', {{IPA|/dɔɡ/}} for ''dog'' and {{IPA|/ˈtʃɔklət/}} for ''chocolate''.

In the varieties of American English that have the lot–cloth split, the ''lot'' vowel is usually symbolized as {{IPA|/ɑ/}}, often called the "short o" for historical reasons, as the corresponding RP vowel {{IPA|/ɒ/}} is still short (and it contrasts with {{IPA|/ɑː/}} as in ''father'' and ''start''). The ''thought'' vowel is usually transcribed as {{IPA|/ɔ/}} and it is often called the "open o". Its actual phonetic realization may be open {{IPAblink|ɒ}}, whereas the ''lot'' vowel may be realized as central {{IPAblink|ä}}. Some words vary as to which vowel they have. For example, words that end in ''-og'' like ''frog'', ''hog'', ''fog'', ''log'', ''bog'' etc. have {{IPA|/ɑ/}} rather than {{IPA|/ɔ/}} in some accents.

There are also significant complexities in the pronunciation of written ''o'' occurring before one of the triggering phonemes {{IPA|/f θ s ŋ ɡ/}} in a non-final syllable.  However, the use of the open o as opposed to the short o is largely predictable.  Just like with /æ/-tensing and the trap–bath split, there seems to be an open-syllable constraint.  Namely, the change did not affect words with /ɑ/ in open syllables unless they were closely derived from words with {{IPA|/ɑ/}} in close syllables.  Hence {{IPA|/ɔ/}} occurs in ''crossing'', ''crosser'', ''crosses'' because it occurs in ''cross''; likewise in ''longing'', ''longer'', ''longest'' because it occurs in ''long''.  However, ''possible'', ''jostle'', ''impostor'', ''profit'', ''Gothic'', ''bongo'', ''Congo'', and ''boggle'' all have {{IPA|/ɑ/}}. However, there are still exceptions in words like ''Boston'' and ''foster''.<ref>{{Cite Merriam-Webster|possible}}</ref><ref>{{Cite Merriam-Webster|jostle}}</ref><ref>{{Cite Merriam-Webster|impostor}}</ref><ref>{{Cite Merriam-Webster|profit}}</ref><ref>{{Cite Merriam-Webster|Gothic}}</ref><ref>{{Cite Merriam-Webster|bongo}}</ref><ref>{{Cite Merriam-Webster|Congo}}</ref><ref>{{Cite Merriam-Webster|Boston}}</ref><ref>{{Cite Merriam-Webster|foster}}</ref> A further list of words is mentioned in the table below:

{| class="wikitable"
|+Vowels with lot–cloth splits
|-
!scope="col"| Set
!scope="col"| {{sc2|THOUGHT}} ({{IPA|/ɔ/}})
!scope="col"| {{sc|LOT}} ({{IPA|/ɑ/}})
!scope="col"| Variable
|-
!scope="row"| {{IPA|/-f/}}
| off, office, cough, etc. || profit || coffee, offer
|-
!scope="row"| {{IPA|/-ft/}}
| soft, loft, etc || waft || {{N/A}}
|-
!scope="row"| {{IPA|/-g/}}
| dog || boggle, cog, flog || blog, frog, hog, log, fog, soggy, tog
|-
!scope="row"| {{IPA|/-k/}}
| chocolate || ''all other words in this set'' || mock
|-
!scope="row"| {{IPA|/-n/}}
| gone || ''all other words in this set'' || on, beyond, want, wont
|-
!scope="row"| {{IPA|/-ŋ/}}
| long, longest, strong, wrong, etc. || bongo, Congo || donkey
|-
!scope="row"| {{IPA|/-s/}}
| loss, boss, etc. || possible, jostle || {{N/A}}
|-
!scope="row"| {{IPA|/-st/}}
| Boston, foster, lost, etc. || roster || {{N/A}}
|-
!scope="row"| {{IPA|/-ʃ/}}
| wash || dosh, nosh, posh, tosh || gosh, quash, squash
|-
!scope="row"| {{IPA|/-θ/}}
| cloth, moth, broth, etc. || Goth, Gothic || sloth, troth
|}

Some words may vary depending on the speaker like (''coffee'', ''offer'', ''donkey'', ''soggy'', ''boondoggle'', etc. with either {{IPA|/ɑ/}} or {{IPA|/ɔ/}}).{{citation needed|date=May 2017}}  Meanwhile, other words vary by region.  For example, the word ''on'', which in Northern American English dialects without the cot-caught merger is pronounced {{IPA|/ɑn/}}, rhyming with ''don'', but in Midland and Southern American English without the merger is pronounced {{IPA|/ɔn/}}, rhyming with ''dawn''. The isogloss for this difference, termed the ''ON line'', lies between {{wipe|New York City}} and Philadelphia on the East Coast and runs West as far as speakers without the merger can be found.{{sfnp|Labov|Ash|Boberg|2006|p=189}}

==''Cot–caught'' merger==

The ''cot''–''caught'' merger (also known as the low back merger or the [[Social:Lexical set|{{sc2|LOT–THOUGHT}}]] merger) is a phonemic merger occurring in many accents of English, where the vowel sound in words like ''cot'', ''nod'', and ''stock'' (the {{sc2|LOT}} vowel), has merged with that of ''caught'', ''gnawed'', and ''stalk'' (the {{sc2|THOUGHT}} vowel). For example, with the merger, ''cot'' and ''caught'' become perfect [[Philosophy:Homophone|homophone]]s.

{| class="wikitable" style="text-align: center;"
|+Lexical changes in cot–caught merger dialects
!scope="col"|[[Social:Lexical set|Lexical set]]
!scope="col"|Example words
!scope="col"|Change
!scope="col"|[[Social:General American|GenAm]] phonemes
!scope="col"|Minimal pairs
!scope="col"|IPA
!scope="col"|Change
!scope="col"|Cot–caught merger dialects
|-
!scope="row"|{{sc2|PALM}}
|'''ah''', f'''a'''ther, sp'''a'''
| rowspan="2" |Father-bother<br/>merger
| rowspan="2" |{{IPA|/ɑ/}}
| rowspan="2" |c'''o'''t, c'''o'''llar, st'''o'''ck,<br/>w'''o'''k, ch'''o'''ck, D'''o'''n
| rowspan="2" |{{IPA|/kɑt/}}, {{IPA|/ˈkɑlər/}}, {{IPA|/stɑk/}},<br/>{{IPA|/wɑk/}}, {{IPA|/tʃɑk/}}, {{IPA|/dɑn/}}
| rowspan="4" |Cot–caught<br />merger
| rowspan="4" |{{IPA|/kɑt/}}, {{IPA|/ˈkɑlər/}}, {{IPA|/stɑk/}},<br/>{{IPA|/wɑk/}}, {{IPA|/tʃɑk/}}, {{IPA|/dɑn/}}
|-
!scope="row"|{{sc2|LOT}}
|b'''o'''ther, l'''o'''t, w'''a'''sp
|-
!scope="row"|{{sc2|CLOTH}}
|b'''o'''ss, cl'''o'''th, d'''o'''g, '''o'''ff
| rowspan="2" |Cloth-thought<br/>merger
| rowspan="2" |{{IPA|/ɔ/}}
| rowspan="2" |c'''augh'''t, c'''al'''ler, st'''al'''k,<br/>w'''al'''k, ch'''al'''k, d'''aw'''n
| rowspan="2" |{{IPA|/kɔt/}}, {{IPA|/ˈkɔlər/}}, {{IPA|/stɔk/}},<br/>{{IPA|/wɔk/}}, {{IPA|/tʃɔk/}}, {{IPA|/dɔn/}}
|-
!scope="row"|{{sc2|THOUGHT}}
|'''a'''ll, th'''ough'''t, fl'''au'''nt
|}

== Other changes ==

=== {{sc2|GOAT–THOUGHT}} merger ===
The '''{{sc2|GOAT–THOUGHT}} merger''' is a merger of the English vowels {{IPA|/oʊ/}} and {{IPA|/ɔː/}} that occurs in Bradford English and sometimes also in Geordie and Northern Welsh English.

=== {{sc2|THOUGHT–FOOT-GOOSE}} merger ===
The '''{{sc2|THOUGHT–FOOT}} merger''' is a merger of the English vowels {{IPA|/ɔː/}} and {{IPA|/ʊ/}} that occurs in morphologically closed syllables in Cockney, rendering ''fought'' homophonous with ''foot'' as {{IPA|[ˈfʊʔ]}}. It is possible only in fast speech.

The '''{{sc2|THOUGHT–GOOSE}} merger''' is a merger of the English vowels {{IPA|/ɔː/}} and {{IPA|/uː/}} that occurs in Cockney, rendering ''hoard'' homophonous with ''who'd'' as {{IPA|[ˈʊd]}}, with the vowel quality that is typical of {{sc2|FOOT}}. It is possible only in fast speech and, in the case of {{IPA|/ɔː/}} (but not {{IPA|/uː/}}), only in morphologically closed syllables.

=== {{sc2|THOUGHT}} split ===
In some London accents of English, the vowel in words such as ''thought,'' ''force,'' and ''north,'' which merged earlier on in these varieties of English, undergoes a conditional split based on syllable structure: closed syllables have a higher vowel quality such as {{IPA|[oː]}} (possibly even {{IPA|[oʊ]}} in broad Cockney varieties), and open syllables have a lower vowel quality {{IPA|[ɔ̝ː]}} or a centering diphthong {{IPA|[ɔə]}}.

Originally-open syllables with an inflectional suffix (such as ''bored'') retain the lower vowel quality, creating minimal pairs such as ''bored'' {{IPA|[bɔəd]}} vs. ''board'' {{IPA|[boːd]}}.{{sfnp|Ostalski|2009|pp=106–107}}

In broad Geordie, some {{sc2|THOUGHT}} words (roughly, those spelled with ''a'', as in ''walk'' and ''talk'') have {{IPAblink|aː}} (which phonetically is the long counterpart of {{sc2|TRAP}} {{IPA|/a/}}) instead of the standard {{IPAblink|ɔː}}. Those are the traditional dialect forms which are being replaced with the standard {{IPAblink|ɔː}}. {{IPAblink|aː}} is therefore not necessarily a distinct phoneme in the vowel system of Geordie, also because it occurs as an allophone of {{IPA|/a/}} before voiced consonants.{{sfnp|Wells|1982|pp=360, 375}}

== Distribution of /ɑː/ ==
The distribution of the vowel transcribed with {{angbr IPA|ɑː}} in broad IPA varies greatly among dialects. It corresponds to {{IPA|/æ/}}, {{IPA|/ɒ/}}, {{IPA|/ɔː/}} and (when not prevocalic within the same word) {{IPA|/ɑːr/}} and even {{IPA|/ɔːr/}} in other dialects:
* In non-rhotic dialects spoken outside of North America, {{IPA|/ɑː/}} corresponds mostly to {{IPA|/ɑːr/}} in General American and so is most often spelled {{angbr|ar}}. In dialects with the trap–bath split (such as Received Pronunciation, New Zealand English and South African English), it also corresponds to GA {{IPA|/æ/}}, which means that it can also be spelled {{angbr|a}} before voiceless fricatives. In those dialects, {{IPA|/ɒ/}} and {{IPA|/ɔː/}} are separate phonemes.
* In native words, {{IPA|/ɑː/}} in most non-rhotic speech of North America corresponds to both {{IPA|/ɑːr/}} in GA (RP {{IPA|/ɑː/}}) and {{IPA|/ɒ/}} in RP, as those dialects feature the father–bother merger.
* North American English features the ''father–bother'' merger, where {{IPA|/ɑː/}} often corresponds to {{IPA|/ɒ/}} in RP. Only New York City English and New England English distinguish between the two, and with an unrounded <small>LOT</small> vowel. Modern-day New York City English also has rounded {{IPA|/ɒː/}} for reflexes of <small>PALM</small>, which ironically, came from an unrounded vowel.
* The is the cot–caught merger usually occurs in addition to the father-bother merger. This applies to almost all of Canadian English and many varieties of American English. The result is usually {{IPA|/ɑ(ː)/}}, the <small>PALM</small> vowel, which is used for <small>LOT</small> as well. Some dialects will have {{IPA|/ɒ(ː)/}} as the merged vowel, not {{IPA|/ɑ(ː)/}}; these include Standard Canadian English or Pittsburgh English.
** The ''caught-cot'' merger ''without'' the ''father-bother'' merger is found in Scottish English and most of New England English. Uniquely, Scottish English merges the <small>LOT</small> vowel into the <small>THOUGHT</small> vowel, rather than the other way around.
* In loanwords and names, the open central unrounded vowel {{IPAblink|ä}} in a source language is regularly approximated with {{IPA|/ɑ(ː)/}} in North America and {{IPA|/æ/}} in RP. However, in the case of mid back rounded vowels spelled {{angbr|o}}, the usual North American approximation is {{IPA|/oʊ/}}, not {{IPA|/ɑː/}} (in RP, it can be either {{IPA|/əʊ/}} or {{IPA|/ɒ/}}). However, when the vowel is both stressed and word-final, the only possibilities in RP are {{IPA|/ɑː/}} in the first case and {{IPA|/əʊ/}} in the latter case, mirroring GA.

For the sake of simplicity, instances of an unrounded {{sc2|LOT}} vowel (phonetically {{IPAblink|ɑ}}) that do not merge with {{sc2|PALM}}/{{sc2|START}} are excluded from the table below. For this reason, the traditional Norfolk dialect is included but the contemporary one, nor the Cardiff dialect, are not.

{| class="wikitable mw-collapsible"
|+ {{IPA|/ɑː/}} in native words and non-recent loanwords
! rowspan="2" | Variety
! rowspan="2" | Rhotic
! colspan="9" | Mergers and splits
! colspan="6" | Possible spellings
|-
! {{small|{{IPA|/ɒrV-ɑːrV/}} merger}}
! {{small|card-cord merger}}
! {{small|cot-caught merger}}
! {{small|father-bother merger}}
! {{small|father-farther merger}}
! {{small|god-guard merger}}
! {{small|lot-cloth split}}
! {{small|trap-palm merger}}
! {{small|trap-bath split}}
! {{angbr|a}}
! {{angbr|ar}}
! {{angbr|au}}{{efn|Excluding words with anomalous pronunciations of <au> like ''laugh'' and ''aunt''.}} 
! {{angbr|aw}}
! {{angbr|o}}
! {{angbr|or}}
|-
! [[Social:Australian English|Australian English]]
| no
| no
| no
| no
| no
| yes
| no
| no
| no
| partial{{efn|Complete before voiceless fricatives: /-f/, /-s/, /-θ/ but variable before nasals: /-mpəl/, /-nd/, /-nt/, /-ntʃ/, /-ns/}} 
| yes
| yes
| no
| no
| no
| no
|-
! Canadian English
| yes
| no
| no
| yes
| yes
| {{N/A}}
| {{N/A}}
| {{N/A}}
| no
| no
| yes
| no
| yes
| yes
| yes
| no
|-
! [[Social:General American|General American]]
| yes
| no
| no
| variable
| yes
| {{N/A}}
| {{N/A}}
| yes
| no
| no
| yes
| no
| variable
| variable
| yes
| no
|-
! Hiberno-English
| yes
| no
| no
| variable
| no
| {{N/A}}
| {{N/A}}
| variable
| variable
| variable
| variable
| no
| no
| no
| no
| no
|-
! New York City English
| variable
| possible
| no
| no
| variable
| variable
| variable
| yes
| no
| no
| yes
| no
| no
| no
| variable
| no
|-
! New Zealand English
| mostly no
| no
| no
| no
| no
| mostly yes
| no
| no
| no
| yes
| yes
| mostly yes
| no
| no
| no
| no
|-
! Northeastern New England English
| no
| no
| no
| yes
| no
| yes
| no
| {{N/A}}
| no
| no
| yes
| yes
| no
| no
| no
| no
|-
! Northern England English
| no
| no
| no
| no
| no
| yes
| no
| no
| no
| no
| yes
| yes
| no
| no
| no
| no
|-
! Philadelphia English
| yes
| possible
| no
| no
| yes
| {{N/A}}
| {{N/A}}
| yes
| no
| no
| yes
| no
| no
| no
| yes
| no
|-
! [[Social:Received Pronunciation|Received Pronunciation]]
| no
| no
| no
| no
| no
| yes
| no
| no
| no
| yes
| yes
| yes
| no
| no
| no
| no
|-
! Scottish English
| yes
| no
| no
| mostly yes
| no
| no
| no
| (unclear)
| mostly yes
| mostly no
| mostly no
| no
| no
| no
| no
| no
|-
! South African English
| mostly no
| no
| no
| no
| no
| mostly yes
| no
| variable
| no
| yes
| yes
| mostly yes
| no
| no
| no
| no
|-
! Southern American English
| variable
| mostly no
| mostly no
| variable
| yes
| variable
| variable
| yes
| no
| no
| yes
| variable
| variable
| variable
| yes
| mostly no
|-
! Traditional Norfolk dialect
| no
| variable
| no
| no
| variable
| yes
| variable
| yes
| no
| yes
| yes
| yes
| no
| no
| yes
| no
|-
! Welsh English
| mostly no
| no
| no
| no
| no
| mostly yes
| no
| no
| no
| variable
| yes
| yes
| no
| no
| no
| no
|}

== Fronted /oʊ/ ==
<!-- Note to editors, this seems to be worth-noting on "a" Wikipedia page.  However, which one remains in question.  Therefore, if you don't think this is the appropriate page for this material, we can discuss this one on the talk page.-->
In many dialects of English, the vowel {{IPA|/oʊ/}} has undergone fronting.  The exact phonetic value varies.  Dialects with the fronted {{IPA|/oʊ/}} include Received Pronunciation; Southern, Midland, and Mid-Atlantic American English; and Australian English.  This fronting does not generally occur before {{IPA|/l/}}, a relatively retracted consonant.

== Table ==
{| class="wikitable mw-collapsible" style="text-align: center;"
|+ Stages leading to some of the open back vowels of General American, summarized from Wells (1982), with the ''cot''–''caught'' merger added
! || ''law''<br>''ball''<br>''taught''<br>''caught'' || ''off''<br>''cloth''<br>''loss'' || ''lot''<br>''stop''<br>''rob''<br>''cot''<br>''bother'' || ''father''<br>''palm''<br>''calm''
|- style="vertical-align: middle;"
! Middle English
| {{IPA|au̯}} || colspan="2" | {{IPA|ɔ}} || {{IPA|a}}
|- style="vertical-align: middle;"
! Quality change
| {{IPA|au̯}}
| colspan="2" | {{IPA|ɒ}} 
| {{IPA|a}}
|- style="vertical-align: middle;"
! ''Thought''-monophthonging
| {{IPA|ɔː}}
| colspan="2" | {{IPA|ɒ}} 
| {{IPA|a}}
|- style="vertical-align: middle;"
! Pre-fricative lengthening
| {{IPA|ɔː}}
| {{IPA|ɒː}}
| {{IPA|ɒ}}
| {{IPA|a}}
|- style="vertical-align: middle;"
! ''A''-lengthening
| {{IPA|ɔː}}
| {{IPA|ɒː}}
| {{IPA|ɒ}}
| {{IPA|aː}}
|- style="vertical-align: middle;"
! Quality change
| {{IPA|ɔː}}
| {{IPA|ɒː}}
| {{IPA|ɒ}}
| {{IPA|ɑː}}
|- style="vertical-align: middle;"
! ''Lot''-unrounding
| {{IPA|ɔː}}
| {{IPA|ɒː}}
| {{IPA|ɑ}}
| {{IPA|ɑː}}
|- style="vertical-align: middle;"
! Loss of distinctive length
| {{IPA|ɔ}} || {{IPA|ɒ}} || {{IPA|ɑ}} || {{IPA|ɑ}}
|- style="vertical-align: top;"
! ''Cloth''–''thought'' merger
| {{IPA|ɔ}} || {{IPA|ɔ}}
| {{IPA|ɑ}}
| {{IPA|ɑ}}
|- style="vertical-align: top;"
! General American output
| colspan="2" | {{IPA|ɔ}} || colspan="2" | {{IPA|ɑ}}
|- style="vertical-align: top;"
! ''Cot''–''caught'' merger
| colspan="4" | {{IPA|ɑ}} 
|}

==See also==

* Phonological history of the English language
* Phonological history of English vowels

== Notes ==
{{notelist|30em}}
==References==
{{Reflist|30em}}

==Bibliography==
* {{cite book
|last=Barber
|first=Charles Laurence
|title=Early modern English
|edition=second
|location=Edinburgh
|publisher=Edinburgh University Press
|year=1997
|isbn=0-7486-0835-4
|url=https://books.google.com/books?id=Iat4Bk_YeR4C
}}
* {{cite book
|last1=Labov
|first1=William
|last2=Ash
|first2=Sharon
|last3=Boberg
|first3=Charles
|title=The Atlas of North American English: Phonetics, Phonology, and Sound Change: a Multimedia Reference Tool
|publisher=Walter de Gruyter
|year= 2006
|isbn=3-11-016746-8
|location=Berlin; New York
|url=https://books.google.com/books?id=qa4-dFqi6iMC
}}
* {{cite journal
|last=Ostalski
|first=Przemysław
|title=Back Vowels in British and American English
|journal=Przedsiębiorczość I Zarządzanie
|volume=5
|issue=4
|year=2009
|pages= 105–118
|url=http://www.swspiz.pl/wydawnictwo/pliki/2009/X-4.pdf
|access-date=2 February 2016
}}


{{DEFAULTSORT:Phonological History Of English Open Back Vowels}}
[[Category:Sociolinguistics]]

{{Sourceattribution|Phonological history of English open back vowels}}