There are a variety of pronunciations in Modern English and in historical forms of the language for words spelled with the letter . Most of these go back to the low vowel (the "short A") of earlier Middle English, which later developed both long and short forms. The sound of the long vowel was altered in the Great Vowel Shift, but later a new long A (or "broad A") developed which was not subject to the shift. These processes have produced the main four pronunciations of in present-day English: those found in the words trap, face, father and square (with the phonetic output depending on whether the dialect is rhotic or not, and, in rhotic dialects, whether or not the Mary–merry merger occurs). Separate developments have produced additional pronunciations in words like wash, talk and comma.

Overview

Late Middle English had two phonemes and , differing only in length. The ("short A") was found in words such as cat and trap , and also before in words such as start . The ("long A") was found in words such as face , and before in words such as scare . This long A was generally a result of Middle English open syllable lengthening. For a summary of the various developments in Old and Middle English that led to these vowels, see English historical vowel correspondences.

As a result of the Great Vowel Shift, the long of face was raised, initially to and later to . After 1700 it was raised even further, and then diphthongized, leading to the modern standard pronunciation . Additionally, the short of trap was fronted to ; this change became accepted in standard speech during the 17th century. Today there is much regional variation in the realization of this vowel; in RP there has been a recent trend for it to be lowered again to a fully open .

These trends, allowed to operate unrestrictedly, would have left standard English without any vowels in the or area by the late 17th century. However, this putative gap was filled by the following special developments: In two environments, Middle English developed to rather than Before non-prevocalic (e.g. in start, star; but not in carry), developed to in all words Before some fricatives, broadening happened inconsistently and sporadically Words that had Middle English had a regular development to (for example, paw). However, before a nasal, such words sometimes instead developed to (e.g. palm).

The of the late 17th century has generally backed to in several varieties of contemporary English, for example in Received Pronunciation.

The following table shows some developments of Middle English in Received Pronunciation. The word gate, which derived from Middle English , has also been included for comparison.

gate cast cart cat glad Middle English Great Vowel ShiftPhase 1Phase 2Phase 3Phase 4 Lengthening before Lengthening before Fronting of Backing of -dropping bad–lad splitOnly some speakers, mainly from London. Lowering of

The table below shows the results of these developments in some contemporary varieties of English:

RP NE SCO IRL GA AusE NZE Lengthening before ✔ ✔variable ✔ ✔ ✔ Lengthening before ✔variable variable ✔ Fronting of ✔ ✔ ✔ ✔ ✔ Backing of ✔ ✔ partly partly R-dropping ✔ ✔ ✔ ✔ bad–lad split ✔✔✔ tensing✔Labov et al. (2006), p. 182. Lowering of ✔variable ✔ Output for gate cast * cart cat glad gas * May undergo -tensing.

Old and Middle English

Old English (OE) had an open back vowel , written , as well as a front vowel , written . These had corresponding long vowels and but were not normally distinguished from the short vowels in spelling although modern editions of Old English texts often mark them as and . In the low vowel area, there was also a pair of short and long diphthongs, and , written (the long one also in modern editions).

In Middle English (ME), the short became merged into a single vowel , written . In some cases (before certain pairs of consonants) the corresponding long vowels also developed into this short . Mostly, however, OE and were raised to become Middle English (the sound that often gives in modern spelling), and OE was raised and rounded to become ME (often , in modern spelling). For more details, see English historical vowel correspondences.

During the Middle English period, like other short vowels, the was lengthened in open syllables. Later, with the gradual loss of unstressed endings, many such syllables ceased to be open, but the vowel remained long.

For example, the word name originally had two syllables, the first being open, so the was lengthened; later, the final vowel was dropped, leaving a closed syllable with a long vowel. As a result, there were now two phonemes and , both written , the long one being often indicated by a silent after the following consonant (or, in some cases, by a pronounced vowel after the following consonant, as in naked and bacon).

Further development of Middle English

As a result of the Great Vowel Shift, the long that resulted from Middle English open syllable lengthening was raised, initially to and later to . "seems to have been the normal pronunciation in careful speech before 1650, and after 1650".Dobson, p. 594 After 1700 it was raised even further, and then diphthongized, leading to the modern standard pronunciation , found in words like name, face, bacon. However, some accents, in the north of England and in Scotland, for example, retain a monophthongal pronunciation of this vowel, while other accents have a variety of different diphthongs.

Before (historical) /r/, in words like square, the vowel has become (often practically ) in Standard Southern British, and in General American.

Changes in realization of Independently of the development of the long vowel, the short came to be fronted and raised to . This change was mostly confined to "vulgar or popular" speech in the 16th century, but it gradually replaced the more conservative in the 17th century, and was "generally accepted by careful speakers by about 1670".Dobson, p. 548

This vowel (that of trap, cat, man, bad, etc.) is now normally denoted as . In present-day RP, however, it has lowered to a fully front . Such a quality is also found in the accents of northern England, Wales, Scotland, Ireland, Canada, California and the Caribbean. Raised pronunciations are also found in Southern Hemisphere English, and are also associated with Cockney. For the possibility of phonemic length differentiation, see bad–lad split, below.

Development of the new long A In Modern English, a new phoneme developed that did not exist in Middle English. The phoneme comes from three sources: the word father lengthening from to for an unknown reason (thus splitting from gather); the compensatory lengthening of the short in words like calm, palm, psalm when was lost in this environment; and the lengthening of before in words like car, card, hard, part, etc. In most dialects that developed the broad A class, words containing it joined this new phoneme as well. The new phoneme also became common in onomatopoeic words like baa, ah, ha ha, as well as in foreign borrowed words like spa, taco, llama, drama, piranha, Bahamas, pasta, Bach, many of which vary between and among different dialects of English.

Some of these developments are discussed in detail in the following sections.

Before /r/

In late Middle English, pairs such as cat, cart, were pronounced , respectively, distinguished only by the presence or absence of . However, by the late 17th century they were also distinguished by the quality and length of the vowel. In cat, the vowel had been fronted to , while in cart it had been lengthened to . This latter change seems to have first occurred in the dialects of southern England in the early 15th century, but did not affect Standard English until the later 17th century.Dobson, pp. 517–519 It has affected most varieties of contemporary English, which have distinct vowels in pairs such as cat, cart. In non-rhotic accents, the of cart has been lost; in Standard Southern British the word is pronounced , distinguished from cat only by the quality and length of the vowel.

This lengthening occurred when was followed by non-pre-vocalic ; it did not generally apply before intervocalic (when the was followed by another vowel). Hence the first vowel of carrot and marry has normally remained the same as that of cat (but see the mary–marry–merry merger). However, inflected forms and derivatives of words ending in (historical) generally inherit the lengthened vowel, so words like barring and starry have as do bar and star.

Before fricatives Unlike lengthening before nonprevocalic , which applied universally in Standard English, lengthening, or broadening, before fricatives was inconsistent and sporadic. This seems to have first occurred in the dialects of Southern England between about 1500 and 1650. It penetrated into Standard English from these dialects around the mid-17th century.

The primary environment which favored broadening was before preconsonantal or morpheme-final voiceless fricatives . The voiceless fricative has never promoted broadening in Standard English in words like ash and crash. There is, however, evidence that such broadening did occur in dialects.Dobson p. 533

Once broadening affected a particular word, it tended to spread by analogy to its inflectional derivatives. For example, from pass () there was also passing . This introduced broadening into the environment _sV, from which it was otherwise excluded (compare passage which is not an inflectional form, and was never affected by broadening).

In a phenomenon going back to Middle English, alternate with their voiced equivalents . For example, late Middle English path alternated with paths . When broadening applied to words such as path, it naturally extended to these derivatives: thus when broadened to , also broadened to . This introduced broadening into the environment before a voiced fricative.

Broadening affected Standard English extremely inconsistently. It seems to have been favored when was adjacent to labial consonants or .Dobson, p. 531 It is apparent that it occurred most commonly in short words, especially monosyllables, that were common and well-established in English at the time broadening took place (c. 1500–1650). Words of 3 or more syllables were hardly ever subject to broadening. Learned words, neologisms (such as gas, first found in the late 17th century), and Latinate or Greek borrowings were rarely broadened.

A particularly interesting case is that of the word father. In late Middle English this was generally pronounced , thus rhyming with gather . Broadening of father is notable both in two respects: its occurrence before an intervocalic voiced fricative its distribution in many accents that do not otherwise have broadening, such as those of North America. The Oxford English Dictionary describes the broadening of father as "anomalous".Oxford English Dictionary, online edition, entry father, retrieved 2011-02-01 Dobson, however, sees broadening in father as due to the influence of the adjacent and combined. Rather and lather appear to have been subject to broadening later, and in fewer varieties of English, by analogy with father.Dobson 531–532

The table below represents the results of broadening before fricatives in Standard Southern British.Words are classified according to their pronunciations given in