Stress and vowel reduction in English


is a prominent feature of the English language, both at the level of the word ' and at the level of the phrase or sentence '. Absence of stress on a syllable, or on a word in some cases, is frequently associated in English with vowel reduction – many such syllables are pronounced with a centralized vowel or with certain other vowels that are described as being "reduced". Various phonological analyses exist for these phenomena.

Lexical and prosodic stress

Lexical stress is regarded as being phonemic in English; the position of the stress is generally unpredictable and can serve to distinguish words. For example, the words insight and incite are distinguished in pronunciation only by the syllable being stressed. In insight, the stress is placed on the first syllable; and in incite, on the second. Similarly, the noun and the verb increase are distinguished by the placement of the stress in the same way – this is an example of an initial-stress-derived noun. 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 : For example, initial-stress pronunciations of offense and defense in American English denote concepts specific to sports, whereas pronunciations with stress on the words' respective second syllables denote concepts related to the legal field and encountered in sports only as borrowed from the legal field in the context of adjudicating rule violations. British English stresses the second syllable in both sports and legal use.
Some words are shown in dictionaries as having two levels of stress: primary and secondary. For example, the RP pronunciation of organization may be given as, with primary stress on the fourth syllable, secondary stress on the first syllable, and the remaining syllables unstressed. For different ways of analysing levels of stress in English, see below.
English also has relatively strong prosodic stress—particular words within a phrase or sentence receive additional stress to emphasize the information they convey. There is also said to be a natural "tonic stress" that falls on the last stressed syllable of a prosodic unit – for more on this, see below under.
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. See.

Reduced vowels

Certain vowel sounds in English are associated strongly with absence of stress: they occur practically exclusively in unstressed syllables; and conversely, most unstressed syllables contain one of these sounds. These are known as reduced vowels, and tend to be characterized by such features as shortness, laxness and central position. The exact set of reduced vowels depends on dialect and speaker; the principal ones are described in the sections below.

Schwa and r-coloured schwa

,, is the most common reduced vowel in English. It may be denoted orthographically by any of the vowel letters, as the a in about, the e in synthesis, the o in harmony, the u in medium, the i in decimal and the y in syringe.
In many rhotic dialects, an r-colored schwa,, occurs in words such as water and standard. Non-rhotic dialects simply have schwa in these positions, except where the dialect has linking R. The r-colored schwa can be analyzed phonemically as.

Reduced vowels in the close unrounded area

In some dialects of English there is a distinction between two vowel heights of reduced vowels: in addition to schwa, there is a distinct near-close central unrounded vowel . In the British phonetic tradition, the latter vowel is represented with the symbol, and in the American tradition. An example of a minimal pair contrasting these two reduced vowels is Rosas vs. roses: the a in Rosa's is a schwa, while the e in roses is the near-close vowel. See weak vowel merger.
This vowel is sometimes informally referred to as schwi in analogy with schwa.
Like schwa, does not correspond in spelling to any single vowel letter. It can be represented by a, e, i, u, or y.
Among speakers who make this distinction, the distributions of schwa and 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. A symbolization convention recently introduced by Oxford University Press for some of their English dictionaries uses the non-IPA "compound" symbol in words that may be pronounced with either or schwa. For example, the word noted is transcribed.
The final vowel of words like happy and coffee is an unstressed front close unrounded vowel most commonly represented with, although some dialects may have. This used to be identified with the phoneme, as in. See happy tensing. However, some contemporary accounts regard it as a symbol representing a close front vowel that is neither the vowel of nor that of ; it occurs in contexts where the contrast between these vowels is neutralized; these contexts include unstressed prevocalic position within the word, such as react. For some speakers, however, there is a contrast between this vowel and in such pairs as taxis vs. taxes and studied vs. studded. See English phonology: § Unstressed syllables under § Vowels.

Reduced vowels in the close rounded area

According to, there is a reduced rounded phoneme as in willow, omission, thus forming a three-way contrast with Willa and Willie or with a mission and emission.
This vowel is sometimes informally referred to as schwu in analogy with schwa.
Analogously to the symbol mentioned [|above], Oxford University Press have devised the non-IPA symbol to represent a vowel that may be either or, the two being in free variation. For example, awful may be pronounced or. Phonologically, this vowel is an archiphoneme representing the neutralization of and.
A rounded vowel, corresponding to the happY vowel, is widely used in British works for words such as influence, into. Phonologically, this vowel is an archiphoneme representing the neutralization of and.

Syllabic consonants

The other sounds that can serve as the peak of reduced syllables are the syllabic consonants. When these occur, there is a syllable with no vowel. The consonants that can be syllabic in English are principally, and. For example, the le in cycle and bottle may be a syllabic, the m in prism may be a syllabic, and the on in prison may be a syllabic. In rhotic accents, and are also realized as syllabic or.
A syllabic consonant may be analyzed phonologically either as just the consonant, or as consisting of an underlying schwa followed by the consonant. For example, cycle may be phonemized as either or. When a syllabic consonant occurs, an alternative pronunciation is also possible. Like the le in cycle, some people pronounce the schwa and the dark l sound while some only pronounce the dark l.

Unstressed full vowels

All full vowels may occur in unstressed position. Some examples of words with unstressed syllables that are often pronounced with full vowels in Received Pronunciation are given below.
Full vowels can often be found in unstressed syllables in compound words, as in bedsheet, moonlit, tentpeg, snowman, and kettledrum. However, in some well-established compounds the vowel of the unstressed part may be reduced, as in postman.
Many other full unstressed vowels also derive historically from stressed vowels, due to shifts of stress over time, or the loss or change of stress in compound words or phrases. There is a tendency, though, for such vowels to become reduced over time, especially in common words.
With vowels represented as and, it may be hard to ascertain whether they represent a full vowel or a reduced vowel. A word that illustrates the contrast is chauvinism, where the first i is the reduced vowel, and the second is unreduced.

Degrees of lexical stress

Descriptions with primary and secondary stress

In many phonological approaches, and in many dictionaries, English is represented as having two levels of stress: primary and secondary. In every lexical word, and in some grammatical words, one syllable is identified as having primary stress, though in monosyllables the stress is not generally marked. In addition, longer words may have one or more syllables identified as having secondary stress. Syllables that have neither primary nor secondary stress are called unstressed.
In International Phonetic Alphabet transcriptions, primary stress is denoted with ˈ and secondary stress with ˌ. IPA stress marks are placed before the stressed syllable. When citing words in English spelling, primary stress is sometimes denoted with an acute accent ´ and secondary stress with a grave accent `, placed over the vowel of the stressed syllable.
Secondary stress is frequently indicated in the following cases:
Note that this last-mentioned group of syllables are those ascribed tertiary stress in the approach described in the next section.

Descriptions with primary, secondary and tertiary stress

In some theories, English has been described as having three levels of stress: primary, secondary, and tertiary. For example, our examples would be ²coun.ter.³in.¹tel.li.gence and ¹coun.ter.³foil. Exact treatments vary, but it is common for tertiary stress to be assigned to those syllables that, while not assigned primary or secondary stress, nonetheless contain full vowels. Dictionaries do not generally mark tertiary stress, but as mentioned above, some of them treat all syllables with unreduced vowels as having at least secondary stress.

Descriptions with only one level of stress

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. According to this view, the posited multiple levels, whether primary–secondary or primary–secondary–tertiary, are mere phonetic detail and not true phonemic stress. They report that often the alleged secondary stress in English is not characterized by the increase in respiratory activity normally associated with primary stress in English or with all stress in other languages. In their analysis, an English syllable may be either stressed or unstressed, and if unstressed, the vowel may be either full or reduced. This is all that is required for a phonemic treatment.
The difference between what is normally called primary and secondary stress, in this analysis, is explained by the observation that the last stressed syllable in a normal prosodic unit receives additional intonational or "tonic" stress. Since a word spoken in isolation, in citation form acquires this additional tonic stress, it may appear to be inherent in the word itself rather than derived from the utterance in which the word occurs.
This combination of lexical stress, phrase- or clause-final prosody, and the lexical reduction of some unstressed vowels, conspires to create the impression of multiple levels of stress. In Ladefoged's approach, our examples are transcribed phonemically as cóunterintélligence, with two stressed syllables, and cóunterfoil, with one. In citation form, or at the end of a prosodic unit, extra stress appears from the utterance that is not inherent in the words themselves: cóunterintélligence and cóunterfoil.
To determine where the actual lexical stress is in a word, one may try pronouncing the word in a phrase, with other words before and after it and without any pauses between them, to eliminate the effects of tonic stress: in the còunterintèlligence commúnity, for example, one can hear secondary stress on two syllables of counterintelligence, as the primary stress has shifted to community.

Comparison

The following table summarizes the relationships between the aforementioned analyses of levels of stress in English: Ladefoged's binary account, a quaternary account, and typical dictionary approaches.
DescriptionExampleBinary
approach		Quaternary approachDictionary approaches
The most prominent syllable when a word is spoken alone.organizationStressedPrimary stressPrimary stress
Other phonetically prominent syllables in a word.organizationStressedSecondary stressSecondary stress
Other syllables with unreduced vowels.counterfoilUnstressedTertiary stressSecondary stress or unstressed
Syllables with reduced vowels.counterfoilUnstressedUnstressed Unstressed

As described in the section above, the binary account explains the distinction observed between "primary" and "secondary" stress as resulting from the prosodic, tonic stress that naturally falls on the final stressed syllable in a unit. It also recognizes the distinction between unstressed syllables with full vowels, and unstressed syllables with reduced vowels, but considers this to be a difference involving vowel reduction and not one of stress.

Distinctions between reduced and unreduced vowels

As mentioned in the previous section, some linguists make a phonemic distinction between syllables that contain reduced vowels, and those that, while being phonetically unstressed, nevertheless contain a full vowel. In some analyses syllables of the latter type are ascribed secondary stress, while in others the reduced/unreduced distinction is regarded as one of vowel quality not involving any difference in stress. This last approach is taken by linguists such as Ladefoged and Bolinger, who thus consider that there are two "tiers" of vowels in English, full and reduced.
A distinction of this type may become useful for the analysis of a potential contrast between words such as humanity, chicory, shivery and manatee, chickaree, shivaree. When assuming a separate set of reduced vowels, the former may end with, while the latter may end with an unreduced. Another example, for some speakers, is provided by the words farrow and Pharaoh; the former may end with a reduced while the latter may end with the unreduced. Alternatively, these reduced vowels can be analyzed as instances of the same phonemes as full vowels. In that case, it may be the phonemic secondary stress that distinguishes these words.
Reduced vowel setSecondary stressNo distinction
shivery – shivaree
farrow – Pharaoh

Some linguists have observed phonetic consequences of vowel reduction that go beyond the pronunciation of the vowel itself. Bolinger observes that a preceding voiceless stop is likely to retain its aspiration before an unstressed full vowel, but not before a reduced vowel; and that flapping of and in American English is possible before a reduced vowel but not before a full vowel. Hence the in manatee would be an aspirated, while that in humanity would be unaspirated or a flap. explains such phenomena by claiming that, in the absence of morpheme boundaries or phonotactical constraints, a consonant between a full and a reduced vowel generally belongs to the syllable with the full vowel, whereas a consonant between two reduced vowels belongs to the preceding syllable. According to this analysis, manatee is and humanity is ; it is then asserted that voiceless stops are only aspirated at the beginning of syllables, and /t/ can only be flapped at the end of a syllable.

Alternation between full and reduced vowels

It is a feature of English that reduced vowels frequently alternate with full vowels: a given word or morpheme may be pronounced with a reduced vowel in some instances and a full vowel in other instances, usually depending on the degree of stress given to it.

Alternation depending on lexical stress

When the stress pattern of words changes, the vowels in certain syllables may switch between full and reduced. For example, in photograph and photographic, where the first syllable has stress and the second syllable is unstressed, the first o is pronounced with a full vowel, and the second o with a reduced vowel. However, in photography and photographer, where the stress moves to the second syllable, the first syllable now contains schwa while the second syllable contains a full vowel.

Alternation depending on meaning

There are a number of English verb-adjective pairs that are distinguished solely by vowel reduction. For example, in some dialects, separate as a verb has a full final vowel,, whereas the corresponding adjective has a reduced vowel: or. A distinction may be made in a similar way between a verb and a noun, as in the case of document. Finally, differences in syllabic stress and vowel reduction may distinguish between meanings even within a given part of speech, with the best-known such pairs in American English being offense and defense.

Alternation depending on type of enunciation

In some words, the reduction of a vowel depends on how quickly or carefully the speaker enunciates the word. 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. Compare this with the o in gallon, which is never a full vowel, no matter how carefully one enunciates.

Weak and strong forms of words

Some monosyllabic English function words have a weak form with a reduced vowel, used when the word has no prosodic stress, and a phonemically distinct strong form with a full vowel, used when the word is stressed. In the case of many such words the strong form is also used when the word comes at the end of a sentence or phrase.
An example of such a word is the modal verb can. When appearing unstressed within a sentence and governing a verb, the weak form is used. However the strong form is used:
In the case of most words with such alternative forms, the weak form is much more common. 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? I found a ' cat.. The weak form of the is typically before a vowel-initial word but before a consonant-initial word, although this distinction is being lost in the United States. A similar distinction is sometimes made with to: to Oxford vs. to Cambridge.
The exact set of words that have weak forms depends on dialect and speaker; the following is a list of the chief words of this type in Received Pronunciation:
In most of the above words the weak form contains schwa, or a syllabic consonant in the case of those ending, or. However, in be, he, me, she, we, been, him the vowel may be the reduced form of, or else ; and in do, who, you it may be the reduced form of, or. These various sounds are described in the section above.
The weak form of that is used only for the conjunction or relative pronoun, and not for the demonstrative pronoun or adjective.
Another common word with a reduced form is our, but this is derived through smoothing rather than vowel reduction.
Other words that have weak forms in many varieties of English include your, and my. These are sometimes given the eye dialect spellings yer and me.
In highly formal registers with exaggeratedly careful enunciation, weak forms may be avoided. An example is singing, where strong forms may be used almost exclusively, apart from a, although weak forms may be used more frequently as tempo increases and note-values shorten.
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 or just the syllabic consonant, or by assimilation with a following velar, as in lock and key. Compare also definite article reduction.
Synchronically, em functions as a weak form of them, though historically it is derived from a different pronoun, the Old English hem.
The homonymy resulting from the use of some of the weak forms can lead to confusion in writing; the identity of the weak forms of have and of sometimes leads to misspellings such as "would of", "could of", etc. for would have, could have, etc.
English weak forms are distinct from the clitic forms found in some languages, which are words fused with an adjacent word, as in Italian mangiarla'', "to-eat-it".

Citations