The English language has undergone a number of phonological changes before the historic phoneme /r/. In recent centuries, most or all of these changes have involved merging of vowel distinctions; in standard American English, for example, although there are ten or eleven stressed monophthongs, only five or six vowel contrasts are possible before a following /r/ in the same syllable (peer, pear, purr, pore, par, tour). Often, more contrasts exist when the /r/ is not in the same syllable; in some American dialects and in most English dialects outside North America, for example, mirror and nearer do not rhyme, and some or all of marry, merry and Mary are pronounced distinctly. (In North America, these distinctions are most likely to occur in New York-New Jersey English, in Eastern New England (including the Boston accent), and in conservative Southern accents.) In nearly all dialects, however, the number of contrasts in this position is reduced, and the tendency is towards further reduction. The difference in how these reductions have been manifested represents one of the greatest sources of cross-dialect variation.

Non-rhotic accents often show mergers in the same positions as rhotic accents do, even though there is often no /r/ phoneme present. This results partly from mergers that occurred before the /r/ was lost, and partly from later mergers of the centering diphthongs and long vowels that resulted from the loss of /r/.

The American phenomenon is one of tense-lax neutralization , where the normal English distinction between tense and lax vowels is eliminated. Such neutralization also occurs in English before /ŋ/, and to a lesser extent before tautosyllabic /ʃ/ and /g/.

In some cases, the quality of a vowel before /r/ is different from the quality of the vowel elsewhere. For example, in American English the quality of the vowel in more typically does not occur except before /r/, and is somewhere in between the vowels of maw and mow. (It is similar to the vowel of the latter word, but without the glide.) Note that a similar situation occurs in many dialects before /ŋ/; the vowel of king, for example, is often pronounced somewhere between those of kin and keen, and may be diphthongal.

Different mergers occur in different dialects. Among United States accents, the Boston and New York accents have the least degree of pre-rhotic merging. Some have observed that rhotic North American accents are more likely to have such merging than non-rhotic accents, but this cannot be said of rhotic British accents like Scottish English, which is firmly rhotic and yet many varieties have all the same vowel contrasts before /r/ as before any other consonant.

Mergers before intervocalic r

Mary-marry-merry merger

One of the best-known pre-rhotic mergers is known as the Mary-marry-merry merger, which consists of the mergers before intervocalic /r/ of /æ/ and /ɛ/ with historical /eɪ/ . This merger is quite widespread in the American West, Inland North, Midland, and in Canada (cf. sample 1). A merger of Mary and merry, while keeping marry distinct, is found in the South and as far north as Baltimore, Maryland, and Wilmington, Delaware; it is also found among Anglophones in Montreal. In the Philadelphia accent the three-way contrast is preserved, but merry tends to be merged with Murray; likewise ferry can be a homophone of furry. See furry-ferry merger below. The three are kept distinct generally outside of North America, as well as in the Philadelphia accent, the New York-New Jersey accent, the Boston accent, and the accent of Providence, Rhode Island (cf. sample 2).

Mirror-nearer merger

Another widespread merger is that of /ɪ/ with /iː/ before intervocalic /r/. For speakers with this merger, mirror and nearer rhyme, and the phrase spear it is homophonous with spirit. This merger seems to be nearly universal in North America, with the major exception again being the northeastern United States, and perhaps conservative Southern accents.

Hurry-furry merger

The merger of /ʌ/ before intervocalic /r/ with /ɝ/ is also widespread in American English apart from the Northeast and the South of the US. Speakers with this merger pronounce hurry to rhyme with furry. In accents that lack the fern-fir-fur merger, hurry and furry rhyme, but they rhyme because they never split in those accents to begin with.

Furry-ferry merger

The merger of (/ɛ/) and (/ʌ/) before /r/ (both neutralized with syllabic r) is common in the Philadelphia accent. This accent does not usually have the marry-merry merger. That is, "short a" (æ) as in carry is a distinct unmerged class before /r/. Thus, Kerry and curry are pronounced the same, but carry is distinct from this pair.

Historic "short o" before intervocalic r

Words that have /ɒ/ before intervocalic /r/ in RP are treated differently in different varieties of North American English. As shown in the table below, in Canadian English, all of these are pronounced with [-ɔr-], as in cord (and thus merge with historic prevocalic /ɔːr/ in words like glory because of the Horse-hoarse merger). In the accents of New York, Philadelphia, and the South, these words are pronounced with [-ɑr-], as in card (and thus merge with historic prevocalic /ɑːr/ in words like starry). In the Boston accent these words are pronounced with [-ɒr-], similar to in RP. Most of the rest of the United States (marked "Gen.Am." in the table), however, has a mixed system: while the majority of words are pronounced as in Canada, the four words in the right-hand column are typically pronounced with [-ɑr-].

RP and Boston /ɒr/
Canada /ɔr/
NYC, Philadelphia, and the South /ɑr/
Gen.Am. /ɔr/	Gen.Am. /ɑr/
foreign Oregon origin Florida forest horrible quarrel warren warranty	borrow sorry sorrow tomorrow

Even in the Northeastern accents without the split (Boston, New York, Philadelphia), some of the words in the original short-o class often show influence from other American dialects and end up with [-ɔr-] anyway. For instance, some speakers from the Northeast may, for example, pronounce Florida, orange, and horrible with [-ɑr-], but foreign and origin with [-ɔr-]. Exactly which words are affected by this differs from dialect to dialect and occasionally from speaker to speaker, an example of sound change by lexical diffusion.

Mergers before historic coda r

Cheer-chair merger

The cheer-chair merger is the merger of the Early Modern English sequences [iːr] and [eːr], which is found in some accents of modern English. Some speakers in New York City and New Zealand merge them in favor of the CHEER vowel, while some speakers in East Anglia and South Carolina merge them in favor of the CHAIR vowel.

Fern-fir-fur merger

The fern-fir-fur merger is the merger of the Middle English vowels into [ɜ] when historically followed by /r/ in the coda of the syllable. As a result of this merger, the vowels in fern, fir and fur are the same in almost all accents of English; the exceptions are Scottish English and some varieties of Hiberno-English. The vowel quality is preserved when vowel-initial suffixes are added to words that came to end in [ɜr] by this merger, so furry has the same vowel as fur and stirring has the same vowel as stir. Otherwise the merger did not happen when the [r] sound was intervocalic, so that mirror, very, and furrow still have distinct vowels.

Fur-fair merger

The fur-fair merger is a merger of /ɜː(r)/ with /ɛə(r)/ that occurs in some accents (for example Liverpool, Dublin, and Belfast) that makes homophonous pairs such as fur/fair, spur/spare, and curd/cared.

It is possible that the merger is found in at least some varieties of African American Vernacular English. In Chingy's song "Right Thurr", the merger is heard at the beginning of the song, but he goes on to use standard pronunciation for the rest of the song (cf. sample 3). In the absence of phonological research in St. Louis, Missouri (Chingy's hometown), it is impossible to know whether there is a genuine phonemic merger here or not.

Stir-steer merger

In older varieties of Southern American English and the West Country accent of English English, words like ear, here, and beard are pronounced /jɝ/, /hjɝ/, /bjɝd/, meaning that there is no complete merger: word pairs like beer and burr are still distinguished as /bjɝ/ vs. /bɝ/. However, if the syllable begins with a consonant cluster (e.g. queer) or a palato-alveolar consonant (e.g. cheer), then there is no /j/ sound: /kwɝ/, /tʃɝ/. It is thus possible that pairs like steer-stir are merged in some accents as /stɝ/, although this is not explicitly reported in the literature.

There is evidence that African American Vernacular English speakers in Memphis, Tennessee, merge both /ɪr/ and /ɛr/ with /ɝ/, so that here and hair are both homophonous with the strong pronunciation of her.

Tower-tire, tower-tar and tire-tar mergers

The tower-tire and tower-tar mergers are vowel mergers in some accents of Southern British English (including many types of RP, as well as the accent of Norwich) that causes the triphthong /aʊə/ of tower to merge either with the /aɪə/ of tire (both surfacing as diphthongal /ɑə/) or with the /ɑː/ of tar. Some speakers merge all three sounds, so that tower, tire, and tar are all homophonous as /tɑː/.

The tire-tar merger, with tower kept distinct, is found in some Midland and Southern U.S. accents.

Cure-fir merger

In East Anglia a merger with the [ɜː] of shirt is common, especially after palatal and palatoalveolar consonants, so that sure is often pronounced [ʃɜː]; yod dropping may apply as well, yielding pronunciations such as [pɜː] for pure. Similarly in American English sure is often pronounced /ʃɝ/. Other American pronunciations showing this merger include /pjɝ/ pure, /ˈkjɝiəs/ curious, /ˈbjɝo/ bureau, /ˈmjɝəl/ mural.

Pour-poor merger

In Modern English dialects, the reflexes of Early Modern English /uːr/ and /iur/ are highly susceptible to phonemic merger with other vowels. Words belonging to this class are most commonly spelled with oor, our, ure, or eur; examples include poor, tour, cure, Europe. Wells refers to this class as the CURE words, after the keyword of the lexical set to which he assigns them.

In traditional Received Pronunciation and General American, CURE words are pronounced with RP /ʊə/ (/ʊər/ before a vowel) and GenAm /ʊr/. But these pronunciations are being replaced by other pronunciations in many English accents.

In English English it is now common to pronounce CURE words with /ɔː/, so that moor is often pronounced /mɔː/, tour /tɔː/, poor /pɔː/. The traditional form is much more common in the northern counties of England. A similar merger is encountered in many varieties of American English, where the pronunciations [oə] or [or]/[ɔr] (depending on whether the accent is rhotic or non-rhotic) prevail.

Pure-poor split

The pure-poor split is a phonemic split that occurs in Australian and New Zealand English that causes the centring diphthong /ʊə/ to disappear and split into /ʉːə/ (a sequence of two separate monophthongs) and /oː/ (a long monophthong), causing pure, cure, and tour to rhyme with fewer, and poor, moor and sure to rhyme with for and paw.

Where the /ʊə/ becomes /ʉːə/ and where it becomes /oː/ is not very predictable. But words spelt with -oor that originally had /ʊə/ become /oː/ perhaps by influence of the words door and floor which rhyme with store in all dialects of English.

A similar split occurs in many varieties of North American English that causes /ʊr/ to disappear and split into /ɝ/ and /ɔr/, causing pure, cure, and sure to rhyme with fir, and poor and moor to rhyme with store and for.

Card-cord merger

The card-cord merger is a merger of Early Modern English [ɑr] with [ɒr], resulting in homophony of pairs like card/cord, barn/born and far/for. The merger is found in some Caribbean English accents, in some versions of the West Country accent in England, and in some Southern and Western U.S. accents. Areas where the merger occurs includes central Texas, Utah, and St. Louis. Dialects with the card-cord merger don't have the horse-hoarse merger. The merger is disappearing in the United States, being replaced by the more common horse-hoarse merger that other regions have.

Horse-hoarse merger

The horse-hoarse merger is the merger of the vowels /ɔ/ and /o/ before historic /r/, making pairs of words like horse/hoarse, for/four, war/wore, or/oar, corps/core, morning/mourning etc. homophones. This merger occurs in most varieties of English. In accents that have the merger horse and hoarse are both pronounced [hɔː(ɹ)s], but in accents that do not have the merger hoarse is pronounced differently, usually [hoɹs] in rhotic and [hoəs] or the like in non-rhotic accents. Non-merging accents include Scottish English, Hiberno-English, the Boston accent, Southern American English, African American Vernacular English, most varieties of Caribbean English, and Indian English.

The distinction was made in traditional Received Pronunciation as represented in the first and second editions of the Oxford English Dictionary. The IPA symbols used are /ɔː/ for horse and /ɔə/ for hoarse.

In the United States, the merger is quite recent in some parts of the country. For example, Kurath and McDavid based on fieldwork performed in the 1930s, shows the contrast robustly present in the speech of Vermont, northern and western New York State, Virginia, central and southern West Virginia, and North Carolina; but Labov, Ash, and Boberg based on telephone surveys conducted in the 1990s, shows these areas as having almost completely undergone the merger. And even in areas where the distinction is still made, the acoustic difference between the [ɔr] of horse and the [or] of hoarse is rather small for many speakers.

The two groups of words merged by this rule are called the lexical sets NORTH (including horse) and the FORCE (including hoarse) by Wells (1982). Etymologically, the NORTH words had /ɒɹ/ and the FORCE words had /oːɹ/. For the most part, the NORTH words are spelled with or followed by a consonant (fork, horse, morning, north, York); the words or, for and nor and all words spelled with war or quar (quarter, war, warm, warn) also belong to this group. The FORCE words are usually spelled with oar (board, coarse, hoarse), oor (door, floor), ore (bore, core, more), and our (course, mourn, pour), and also many words with or followed by another vowel (boring, glory). In addition, there are also several FORCE words with an or spelling before a consonant: most of these are words with a labial consonant before the or, as in pork, port, Portugal, sport, afford, force, ford, forge, divorce, as well as the past participles borne, sworn, torn, worn.

Court-quart merger

The court-quart merger in some varieties of American English is an advancement of both the horse-hoarse merger and the pour-poor merger combined, where all three sounds merge and then migrate to [uɹ]. In such accents, the words court and quart are both pronounced [kuɹt], so that "a quart of milk" can sound like "a court of milk". In situations where distinction is needed, the word quart can be enunciated as [kuːɹt]. Other quar-, whar- and -war- sequences are similarly affected, with the effect that wart becomes [ɦuɹt] (note the [ɦ]), wharf becomes [huɹf] or [ɦuɹf] (depending on whether the wine-whine merger is present), and swarm becomes [suɹm]. This merger is similar in nature to the historic w-dropping in words like who, whore and sword, where /wo(r)/ merged with /oo(r)/.

See also

• Phonological history of the English language
• Phonological history of English vowels
• coil-curl merger
• English phonology
• History of the English language
• Vocalic r

Sound samples

1. http://www.alt-usage-english.org/mmm_bc.wav Sample of a speaker with the Mary-marry-merry merger Text: "Mary, dear, make me merry; say you'll marry me."
2. http://www.alt-usage-english.org/mmm_rf.wav Sample of a speaker with the three-way distinction
3. http://ldc.upenn.edu/myl/thurr.mp3 Text: "I like the way you do that right there (right there)/Swing your hips when you're walkin', let down your hair (let down your hair)/I like the way you do that right there (right there)/Lick your lips when you're talkin', that make me stare"

Notes

References

• Hammond, Michael. (1999). The Phonology of English. Oxford: Oxford University Press. ISBN 0-19-823797-9.
• Kenyon, John S. (1951). American Pronunciation. 10^th edition, Ann Arbor, Michigan: George Wahr Publishing Company.
• Kurath, Hans, and Raven I. McDavid (1961). The Pronunciation of English in the Atlantic States. Ann Arbor: University of Michigan Press. ISBN 0-8173-0129-1.
• Labov, Wiliam, Sharon Ash, and Charles Boberg (2006). The Atlas of North American English. Berlin: Mouton de Gruyter. ISBN 3-11-016746-8.
• Ristuccia, C.L. , Gilbert, D.W. & Ristuccia, J.E. (2005). The Entire World of R Book of Elicitation Techniques. Tybee Island, GA: 'Say It Right'. ISBN 0-9760490-7-4.
• Shitara, Yuko (1993). "A survey of American pronunciation preferences". Speech Hearing and Language 7 201–32.
• Wells, John C. (1982). Accents of English. Cambridge: Cambridge University Press. ISBN 0-521-22919-7 (vol. 1), ISBN 0-521-24224-X (vol. 2), ISBN 0-521-24225-8 (vol. 3).