English-language Vowel Changes Before Historic /r/ - Overview

Overview

In most North American accents, 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, poor). Often, more contrasts exist when the /r/ is not in the same syllable; in some American dialects and in most native 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 City, Philadelphia, Eastern New England (including Boston), 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.

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.)

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.