Stress and vowel reduction in English

Moreover, even within a given letter sequence and a given part of speech, lexical stress may distinguish between different words or between different meanings of the same word (depending on differences in theory about what constitutes a distinct word): for example, initial-stress pronunciations of offense /ˈɔfɛns/ and defense /ˈdifɛns/ in American English denote concepts specific to sports, whereas pronunciations with stress on the words' respective second syllables (offense /əˈfɛns/ and defense /dəˈfɛns/) denote concepts related to the legal (and, for defense, the military) field, and encountered in sports only as borrowed from the legal field in the context of adjudicating rule violations.

English also has relatively strong prosodic stress—particular words within a phrase or sentence receive additional stress to emphasize the information they convey.

English is classified as a stress-timed language, which means that there is a tendency to speak so that the stressed syllables come at roughly equal intervals.

These are known as reduced vowels, and tend to be characterized by such features as shortness, laxness and central position.

[1]) The exact set of reduced vowels depends on dialect and speaker; the principal ones are described in the sections below.

In many rhotic dialects, an r-colored schwa, [ɚ], occurs in words such as water and standard.

It can be represented by a (for example, message [ˈmɛsɪ̈dʒ], climate [ˈklaɪmɪ̈t], orange [ˈɒɹɪ̈ndʒ]), e (puppet), i (limit), u (minute), or y (polyp).

Among speakers who make this distinction, the distributions of schwa and [ɪ̈] are quite variable, and in many cases the two are in free variation: the i in decimal, for example, may be pronounced with either sound.

According to Bolinger (1986:347–360), there is a reduced rounded phoneme /ɵ/ as in willow /ˈwɪlɵ/, omission /ɵˈmɪʃən/, thus forming a three-way contrast with Willa /ˈwɪlə/ and Willie /ˈwɪlɨ/ or with a mission /ə ˈmɪʃən/ and emission /ɨˈmɪʃən/.

The consonants that can be syllabic in English are principally /l/, /m/, and /n/, for example in cycle (spelled by L followed by a silent e), prism, and prison.

Full vowels are commonly, but not always, preserved in unstressed syllables in compound words, such as in bedsheet, moonlit, tentpeg, snowman, and kettledrum.

In many phonological approaches, and in many dictionaries, English is represented as having two levels of stress: primary and secondary.

Phoneticians such as Peter Ladefoged have noted that it is possible to describe English with only one degree of stress, as long as unstressed syllables are phonemically distinguished for vowel reduction.

[21] According to this view, the posited multiple levels, whether primary–secondary or primary–secondary–tertiary, are mere phonetic detail and not true phonemic stress.

In Ladefoged's approach, our examples are transcribed phonemically as cóunterintélligence /ˈkaʊntər.ɪnˈtɛlɪdʒəns/, with two stressed syllables, and cóunterfoil /ˈkaʊntərfɔɪl/, with one.

In citation form, or at the end of a prosodic unit (marked [‖]), extra stress appears from the utterance that is not inherent in the words themselves: cóunterintélligence [ˈkaʊntər.ɪnˈˈtɛlɪdʒəns‖] and cóunterfoil [ˈˈkaʊntərfɔɪl‖].

This approach is taken by linguists such as Ladefoged[22] and Bolinger,[23] who thus consider that there are two "tiers" of vowels in English, full and reduced.

(This contrasts with analyses that ascribe secondary or tertiary stress to syllables with unreduced vowels.)

Finally, differences in syllabic stress and vowel reduction (or lack of the latter) may distinguish between meanings even within a given part of speech, with the best-known such pairs in American English being offense and defense (in each case with the first syllable accented in the context of sports and the second syllable accented in legal contexts).

For example, the o in obscene is commonly reduced to schwa, but in more careful enunciation it may also be pronounced as a full vowel (that of LOT).

This is particularly true of the English articles the, a, an, whose strong forms are used within normal sentences only on the rare occasions when definiteness or indefiniteness is being emphasized: Did you find the cat?

[22][pages needed] A similar distinction is sometimes made with to: to Oxford [tu] vs. to Cambridge [tə].

Another common word with a reduced form is our [ɑɚ]~[ɑː], but this is derived through smoothing rather than vowel reduction.

In highly formal registers with exaggeratedly careful enunciation, weak forms may be avoided.

[citation needed] The vowel reduction in weak forms may be accompanied by other sound changes, such as h-dropping, consonant elision, and assimilation.

For example, and may reduce to [ən] or just the syllabic consonant [n̩], or [ŋ̍] by assimilation with a following velar, as in lock and key.

Synchronically, 'em [əm] functions as a weak form of them, though historically it is derived from a different pronoun, the Old English hem.