Consonants and vowels correspond to distinct parts of a
syllable: The most
sonorous part of the syllable, called the
syllabic peak or
nucleus, is typically a vowel, while the less sonorous margins (called the
onset and
coda) are typically consonants. Such syllables may be abbreviated CV, V, and CVC, where C stands for consonant and V stands for vowel. This can be argued to be the only pattern found in most of the world's languages, and perhaps the primary pattern in all of them. However, the distinction between consonant and vowel is not always clear cut: there are syllabic consonants and non-syllabic vowels in many of the world's languages. One blurry area is in segments variously called
semivowels,
semiconsonants, or
glides. On one side, there are vowel-like segments that are not in themselves syllabic, but form
diphthongs as part of the syllable nucleus, as the
i in English
boil . On the other, there are
approximants that behave like consonants in forming onsets, but are articulated very much like vowels, as the
y in English
yes . Some phonologists model these as both being the underlying vowel , so that the English word
bit would
phonemically be ,
beet would be , and
yield would be phonemically . Likewise,
foot would be ,
food would be ,
wood would be , and
wooed would be . However, there is a (perhaps allophonic) difference in articulation between these segments, with the in
yes and
yield and the of
wooed having more constriction and a more definite place of articulation than the in
boil or
bit or the of
foot. The other problematic area is that of syllabic consonants, segments articulated as consonants but occupying the nucleus of a syllable. This may be the case for words such as
church in
rhotic dialects of English, although phoneticians differ in whether they consider this to be a syllabic consonant, , or a rhotic vowel, : Some distinguish an approximant that corresponds to a vowel , for
rural as or ; others see these as a single phoneme, . Other languages use fricative and often trilled segments as syllabic nuclei, as in
Czech and several languages in
Democratic Republic of the Congo, and
China, including
Mandarin. In Mandarin, they are historically allophones of , and spelled that way in
Pinyin. Ladefoged and Maddieson call these "fricative vowels" and say that "they can usually be thought of as syllabic fricatives that are allophones of vowels". That is, phonetically they are consonants, but phonemically they behave as vowels. Many
Slavic languages allow the trill and the lateral as syllabic nuclei (see
Words without vowels). In languages like
Nuxalk, it is difficult to know what the nucleus of a syllable is, or if all syllables even have nuclei. If the concept of 'syllable' applies in Nuxalk, there are syllabic consonants in words like (?) 'seal fat'.
Miyako in Japan is similar, with 'to build' and 'to pull'. Each spoken consonant can be distinguished by several phonetic
features: • The
manner of articulation is how air escapes from the vocal tract when the consonant or
approximant (vowel-like) sound is made. Manners include stops, fricatives, and nasals. • The
place of articulation is where in the vocal tract the obstruction of the consonant occurs, and which speech organs are involved. Places include
bilabial (both lips),
alveolar (tongue against the gum ridge), and
velar (tongue against soft palate). In addition, there may be a simultaneous narrowing at another place of articulation, such as
palatalisation or
pharyngealisation. Consonants with two simultaneous places of articulation are said to be
coarticulated. • The
phonation of a consonant is how the
vocal cords vibrate during the articulation. When the vocal cords vibrate fully, the consonant is called
voiced; when they do not vibrate at all, it is
voiceless. • The
voice onset time (VOT) indicates the timing of the phonation.
Aspiration is a feature of VOT. • The
airstream mechanism is how the air moving through the vocal tract is powered. Most languages have exclusively
pulmonic egressive consonants, which use the lungs and diaphragm, but
ejectives,
clicks, and
implosives use different mechanisms. • The
length is how long the obstruction of a consonant lasts. This feature is borderline distinctive in English, as in "wholly" vs. "holy" , but cases are limited to morpheme boundaries. Unrelated roots are differentiated in various languages such as Italian, Japanese, and Finnish, with two length levels, "single" and "
geminate".
Estonian and some
Sami languages have three phonemic lengths: short, geminate, and long geminate, although the distinction between the geminate and overlong geminate includes suprasegmental features. • The articulatory force is how much muscular energy is involved. This has been proposed many times, but no distinction relying exclusively on force has ever been demonstrated. All English consonants can be classified by a combination of these features, such as "voiceless alveolar stop" . In this case, the airstream mechanism is omitted. Some pairs of consonants like
p::b,
t::d are sometimes called
fortis and lenis, but this is a
phonological rather than phonetic distinction. Consonants are scheduled by their features in a number of IPA charts: ==Examples==