The sound system of English and its suprasegmentals

Sounds before letters

English spelling is a poor guide to English sound. The letters ough spell different sounds in though, through, tough and cough, while the single sound /iː/ is spelled differently in see, sea, key, field and machine. Linguists therefore write sounds in the symbols of the International Phonetic Alphabet (IPA), where one symbol always stands for one sound. Symbols between slashes, such as /p/, are phonemes; symbols in square brackets, such as [pʰ], are actual speech sounds.

1. Phonemes, allophones and minimal pairs

Say pin and then spin with your hand in front of your mouth. The /p/ of pin comes with a puff of air, written [pʰ] (aspirated); the /p/ of spin has almost none, written [p]. English speakers hear both as "the same p", because swapping them never changes a word into another word. [pʰ] and [p] are allophones of the one phoneme /p/.

Allophones of a phoneme are usually in complementary distribution: each occurs in places where the other never does. Aspirated [pʰ] begins a stressed syllable (pin, appear); plain [p] follows /s/ (spin, spot).

To prove that two sounds are separate phonemes, linguists look for a minimal pair: two words that differ in one sound in the same position and differ in meaning. Pat/bat proves /p/ and /b/ contrast; ship/sheep proves /ɪ/ and /iː/ contrast. A pair like cat/cats is not minimal, because one word has an extra sound.

2. Describing consonants

English has about 24 consonant phonemes. Each is described by three labels: voicing, place and manner of articulation.

Voicing. Put your fingers on your throat and say sss, then zzz. You feel the vocal folds vibrate for /z/: it is voiced; /s/ is voiceless. Many consonants come in voiceless–voiced pairs: /p b/, /t d/, /k g/, /f v/, /θ ð/, /s z/, /ʃ ʒ/, /tʃ dʒ/.

Place is where the airflow is narrowed or blocked.

Manner is how the air is obstructed.

• Stops (plosives) block the air completely, then release it: /p b t d k g/.
• Fricatives narrow the passage so the air hisses through: /f v θ ð s z ʃ ʒ h/.
• Affricates are a stop released into a fricative: /tʃ/ in church, /dʒ/ in judge.
• Nasals let air out through the nose: /m n ŋ/.
• Lateral approximant: /l/, with air passing along the sides of the tongue.
• Approximants (glides and r): /w j r/, where the articulators come close without friction.

3. Describing vowels

Vowels are made with an open vocal tract and are described by the position of the tongue and lips.

• Height – high (close), mid, or low (open): /iː/ in see is high, /æ/ in cat is low.
• Backness – front, central, or back: /iː/ is front, /uː/ in food is back.
• Rounding – rounded lips (/uː/, /ɔː/) or spread lips (/iː/).
• Tense or lax – tense vowels are longer and more peripheral (/iː/ in seat), lax vowels shorter and more central (/ɪ/ in sit).

The most frequent vowel in English is the schwa /ə/, a mid central lax vowel heard only in unstressed syllables: the first syllable of about, the last of sofa, both outer syllables of banana /bəˈnɑːnə/.

A diphthong glides from one vowel quality to another within one syllable: /aɪ/ in my, /aʊ/ in now, /ɔɪ/ in boy, /eɪ/ in day, /oʊ/ (British /əʊ/) in go. A single steady vowel is a monophthong. Counts of English vowel phonemes differ by accent, from about 14 in General American to about 20 in British Received Pronunciation.

4. The syllable

A syllable has a nucleus (or peak), normally a vowel, which every syllable must have. Consonants before it form the onset; consonants after it form the coda. The nucleus and coda together are the rhyme.

• An open syllable ends in its nucleus (see, go); a closed syllable ends in a coda (cat, stop).
• Some consonants can be the nucleus: in button /ˈbʌtn̩/ and bottle /ˈbɒtl̩/ the second syllable is a syllabic /n/ or /l/.
• Phonotactics are a language's rules for combining sounds. English onsets have at most three consonants, and a three-consonant onset always begins with /s/ followed by /p t k/ and then /l r w j/ (spring, split, street, squeeze). /ŋ/ never begins an English word, and /h/ never ends one.

5. Suprasegmentals: stress

Suprasegmental (or prosodic) features belong to stretches of speech larger than one segment. A stressed syllable is louder, longer and higher or more prominent in pitch, and its vowel is full; unstressed vowels often weaken to schwa.

• Word stress is part of a word's identity. PHOtograph, phoTOgraphy, photoGRAPHic: the stress moves with the suffix, and the vowels change with it.
• Noun–verb pairs. Many two-syllable words stress the first syllable as nouns and the second as verbs: a REcord / to reCORD, a PREsent / to preSENT, an OBject / to obJECT, CONduct / conDUCT.
• Suffixes that fix stress. -tion and -ic put the stress on the syllable just before them: eduCAtion, ecoNOmic.
• Compounds. Compound nouns stress the first part: a BLACKboard (for chalk) but a black BOARD (any board that is black); a GREENhouse but a green HOUSE.
• Sentence stress. Content words (nouns, main verbs, adjectives, adverbs) are normally stressed; function words (articles, prepositions, auxiliaries, pronouns) are normally unstressed and take weak forms: to /tə/ in I want to GO, and /ən/ in BREAD and BUTter.
• Contrastive stress moves the main stress to the word being contrasted: I said the BLUE one, not the red one.

Rhythm. English is described as stress-timed: stressed syllables come at roughly regular intervals, and the unstressed syllables between them are squeezed. Spanish and the Philippine languages are closer to syllable-timed, giving each syllable about equal length. Filipino learners therefore often give full vowels to unstressed syllables, and practising schwa and weak forms makes their English easier to follow.

6. Suprasegmentals: pitch, intonation and juncture

Pitch is how high or low the voice is; intonation is the pattern of pitch across a whole utterance. English uses intonation for grammar and attitude, not to tell words apart.

• Falling intonation ends statements (I live in Cebu.↘), wh-questions (Where do you live?↘) and commands.
• Rising intonation ends yes/no questions (Are you coming?↗) and statements used as questions (You're leaving?↗).
• Lists rise on each item and fall on the last: apples↗, mangoes↗ and bananas↘.
• Tag questions fall when the speaker expects agreement (It's hot, isn't it?↘) and rise when the speaker really asks (You paid, didn't you?↗).

Juncture is the way sounds are joined or separated at word boundaries. It is what separates ice cream from I scream, a name from an aim, and night rate from nitrate: the sounds are the same, but the transitions (aspiration, length, a slight pause) differ.

Summary

• Phonetics studies speech sounds; phonology studies the system of contrasts. A phoneme changes meaning; its allophones do not.
• Minimal pairs prove two sounds are separate phonemes; allophones are in complementary distribution.
• Consonants are described by voicing, place (bilabial to glottal) and manner (stop, fricative, affricate, nasal, approximant).
• Vowels are described by height, backness, rounding and tenseness; schwa is the unstressed mid central vowel; diphthongs glide.
• A syllable is onset + nucleus + coda; only the nucleus is required.
• Stress, intonation, juncture and rhythm are suprasegmentals; English is stress-timed.