When pronounced in isolation words that contain more than one syllable will have one of their vowels uttered more prominently than the other(s). For example, in the noun torment toːmɛnt the first vowel, which is underlined, is pronounced with more prominence, in the verb torment toːmɛnt the second one is. Otherwise the two words sound the same. This prominence is usually called stress. Stress has several manifestations: increased loudness, higher pitch, or increased length.
In transcriptions stress can be marked by an accent mark on the stressed vowel (eg tóːmɛnt and toːmɛ́nt) or by a vertical stroke before the stressed syllable (eg ˈtoːmɛnt and toːˈmɛnt). The latter marking of stress conforms to the standards of the IPA, however, its disadvantage is that it presupposes that we know where syllable boundaries fall. There is consensus about syllable division in many cases, but their location is not always obvious and indisputable. Therefore we will simply mark stress by an accent mark on the stressed vowel.»There are cases, like torment, where the location of stress is rather unpredictable — there are strong tendencies though. Neverteless, stress is not marked in any way in English spelling.
Stress and segments
Stress in English is closely related to the vowel that carries it. There is one vowel in English, schwa (ə), which cannot be stressed at all.»This is true provided that we distinguish the vowel of strut, ʌ, and schwa, which we do here. There are other vowels, namely ɪ, ɪi, ʉu, and əu, which may occur both unstressed (eg panic pánɪk, happy hápɪi, value váljʉu, motto mɔ́təu) and stressed (eg litter lɪ́tə, metre mɪ́itə, future fjʉ́uʧə, bogus bə́ugəs). Other vowels only occur stressed. The following list shows the three sets.
only unstressed: ə
ambiguous: ɪ ɪi ʉu əu
only stressed: ɛ a ʌ ɔ ɵ ɪː ɛː ɑː əː oː ɵː ɛi ɑi oi au
We have seen that schwa is the only short vowel which occurs word finally. Three of the ambiguous vowels are diphthongs, ie free vowels, but their distribution is free only when they are stressed. When unstressed their occurrence is restricted. Let us look at the ambiguous vowels one by one.
The ambiguous vowel ɪ
The checked vowel ɪ only occurs before consonants. This constraint holds both when it is stressed and when it is unstressed. Checked vowels never occur at the end of a word or before another vowel.
Many instances of unstressed ɪ are exchangeable by ə, eg exam ɪgzám or əgzám, kisses kɪ́sɪz or kɪ́səz. Unstressed ɪ is stable (ie is not exchangeable by ə) in words that end in ɪʤ (eg village, knowledge), ɪk (eg panic, music), ɪŋ (eg Ewing jʉ́uɪŋ, gosling gɔ́zlɪŋ), or ɪʃ (eg finish, astonish).
The other three ambiguous vowels are differently distributed in unstressed position, so at least in some cases we can tell if they are stressed or unstressed.
The ambiguous vowel ɪi
The diphthong ɪi is a free vowels, so it is found in practically any environment, but only when stressed. Unstressed ɪi only occurs word finally (eg happy hápɪi) and before another vowel (eg create krɪiɛ́it).
That is, we do not find unstressed ɪi before a consonant. “Counterexamples” like carried kárɪid, babies bɛ́bɪiz, or happiness hápɪinəs are only apparent: such words always contain a suffix attached to a free stem. That is, the unstressed ɪi in these words is word final: it is at the end of the word carry, baby and happy.
We do find stressed ɪi both at the end of words (eg agree əgrɪ́i) and before another vowel (eg neon nɪ́iɔn). In these environments the quality of the vowel does not tell us if it is stressed or not, we have to look for other clues.
The ambiguous vowel ʉu
Unstressed ʉu is most common after a palatal consonant, ie j, ʃ, ʒ, ʧ, ʤ, or r (eg value váljʉu, issue ɪ́ʃʉu, usual jʉ́uʒʉuəl, statue stáʧʉu, module mɔ́ʤʉul, erudite ɛ́rʉudɑit). The only case that an unstressed ʉu occurs after a nonpalatal consonant is if there is a “stop+liquid” cluster before it (eg plutonic plʉutɔ́nɪk).
Unstressed ʉu occurs word finally (eg statue stáʧʉu), before a word-final consonant (eg statute stáʧʉut), before a vowel (eg arduous ɑ́ʤʉuəs). It does not occur followed by a consonant and an unstressed vowel. Eg stimulation may be stɪ́mjʉulɛ́iʃən or stɪ́mjəlɛ́iʃən, because the following vowel is stressed, but stimulus may only be stɪ́mjələs (not *stɪ́mjʉuləs) because the following vowel is not stressed. Experts usually say the ʉu in stimulation is in pretonic position (ie it is before a stressed vowel), that in stimulus is not in pretonic position.
The ambiguous vowel əu
The vowel əu is stressed when it is not at the end of a word (eg anecdote ánəkdəut).»You may have noticed that stress is not marked on the last vowel of this word. We will discuss this further below. Word final əu is also usually stressed (eg ago əgə́u). In some words, however, word-final əu behaves like an unstressed vowel (eg motto mɔ́təu). It is not always detectable that it is unstressed, we will see some symptoms of this in the next section.
Consonants before a stressed vowel
Stress is not only related to the vowel which is stressed, but also influences the consonant before it. In some accents of English r only occurs before stressed vowels and not before unstressed ones. The segment h is also similarly distributed in many accents of English: we find h before a stressed vowel, like in vehicular vəhɪ́kjələ, but not before and unstressed one, like in vehicle vɪ́i əkəl.»Some, like Cockney, do not have a h at all. The consonant h also occurs at the beginning of words, but this is not related to stress.
Aspiration and flapping are also sensitive to the stress of the following vowel.
Levels of stress?
Many descriptions of English stress talk about more than one degrees of stress. Indeed, in words that have more than one stressed vowels one of these stresses is stronger than the other. For example, in words like aspiration áspərɛ́iʃən or fourteen fóːtɪ́in, where two vowels are stressed, the first stress is weaker than the last one. These weaker stresses are called secondary stress — as opposed to the stronger primary stress. To distinguish the two, another stress mark has to be introduced. The usual convention is to use the grave accent mark for secondary stress and the acute accent mark for primary stress, as in àspərɛ́iʃən and fòːtɪ́in. The standard IPA convention is a vertical stroke on the baseline, but again this requires that we always know exactly where syllable boundaries fall, as in ˌaspəˈrɛiʃən and ˌfoːˈtɪin.
Note, however, that in words like aspiration or fourteen it is always the last stress that is most prominent. So there is no point in distinguishing the “two degrees” of stress, since this is a predictable difference, much like the fact that vowels are shorter before fortis consonants than elsewhere. What is more, the last stress is necessarily the most prominent one only if the word is pronounced in isolation, as a complete utterance. But in normal language use, this is not the default case, words are typically pronounced in conjunction in other words. In such cases very often the first stress will be more prominent than the second one. Thus in aspiration rule áspərɛ̀iʃən rʉ́ul or in fourteen days fóːtɪ̀n dɛ́iz the first and not the second stress of the first word is more prominent. This phenomenon is called stress shift. In fact, we only need to talk about stress shift only if we distinguish the prominence of stresses in words. If — as suggested here — we simply mark each stressed vowel as such, there is no need to mark stress shift at all: áspərɛ́iʃən and fóːtɪ́in remain unchanged in áspərɛ́iʃən rʉ́ul and fóːtɪ́n dɛ́iz the prominence of each stress is not the business of the words involved, but is decided at a higher level, when the words are bound together. That is, we do not have to mark stress prominence in individual words, just like we do not have to mark intonation contours in them.
last touched 2014-11-02 00:53:45 +0100