Difficulty: Introductory to Intermediate | Prerequisites: English grammar, English phonetics
Phonetics and phonology are the two branches of linguistics concerned with speech sounds, and they form the foundation of everything else in this course. Phonetics deals with the physical properties of sounds: how they are produced, transmitted and perceived. Phonology deals with how sounds function within a particular language system, which ones count as distinct and which are simply variants of the same unit. If you skipped the English Phonetics prerequisite, revisit IPA basics before going further.
Phonetics studies speech sounds as physical events (articulation, acoustics, perception). Phonology studies how a given language organises those sounds into a system of contrasts. The dividing line: phonetics asks "what sounds can humans make?", phonology asks "which sound differences matter in this language?"
Phonetics
The scientific study of speech sounds as physical phenomena, covering their production, transmission and perception. In simple terms, it is the study of what sounds humans can make and how those sounds physically work.
Phonology
The branch of linguistics concerned with how sounds function and pattern within a specific language. Think of it as the "grammar of sounds": which differences between sounds actually change the meaning of a word.
Phone
Any speech sound considered as a physical event, regardless of its function in a language. Written in square brackets, e.g. [p]. In simple terms, a phone is just a sound you can hear and record, no questions asked about what it "means."
Phoneme
The smallest unit of sound that can distinguish one word from another in a given language. Written between slashes, e.g. /p/. Think of it as a sound category that speakers of a language treat as meaningfully different from other categories.
Allophone
A predictable phonetic variant of a phoneme that occurs in a specific environment. Allophones of the same phoneme never cause a change in meaning. In simple terms, allophones are different "versions" of the same phoneme. English speakers do not usually notice the difference between them.
Minimal pair
Two words that differ in exactly one phoneme in the same position, and have different meanings (e.g. "pat" /pæt/ vs "bat" /bæt/). This is the classic test for whether two sounds are separate phonemes.
IPA (International Phonetic Alphabet)
A standardised set of symbols where each symbol represents one and only one speech sound. Used across languages. Think of it as a universal spelling system for pronunciation.
Articulatory phonetics
The sub-branch of phonetics that studies how the vocal organs (tongue, lips, larynx, etc.) produce speech sounds.
Acoustic phonetics
The sub-branch that studies the physical properties (frequency, amplitude, duration) of speech sounds as sound waves.
Auditory phonetics
The sub-branch that studies how the ear and brain perceive and process speech sounds.
Voiced / voiceless
Voiced sounds are produced with vocal cord vibration (e.g. /b/, /d/, /g/). Voiceless sounds are produced without it (e.g. /p/, /t/, /k/). Place your fingers on your throat and say "zzz" then "sss": the buzz you feel on "zzz" is voicing.
Place of articulation
Where in the vocal tract a consonant's major obstruction occurs (e.g. bilabial, alveolar, velar).
Manner of articulation
How the airstream is modified to produce a consonant (e.g. stop/plosive, fricative, nasal, affricate, approximant).
Aspiration
A puff of air that follows certain voiceless stops in English when they appear at the beginning of a stressed syllable (e.g. the [pʰ] in "pin"). Aspiration is allophonic in English: [pʰ] and [p] are both allophones of /p/.
Complementary distribution
Two sounds are in complementary distribution when they never occur in the same phonetic environment. This is evidence that they are allophones of the same phoneme.
Free variation
When two sounds can appear in the same environment without changing the meaning. They may be allophones of the same phoneme.
Suprasegmental features
Phonological features that extend over more than one sound segment, including stress, tone, intonation and length.
Articulatory phonetics studies the movement of speech organs (lungs, larynx, tongue, lips, velum, teeth, alveolar ridge). This is the branch emphasised most in introductory courses because it gives you the vocabulary to describe any consonant or vowel.
Acoustic phonetics analyses speech as sound waves using instruments such as spectrograms. Key measurements include fundamental frequency (pitch), formants (vowel quality) and voice onset time (VOT).
Auditory phonetics examines how the listener's ear and brain decode speech signals. Less commonly tested at this level, but relevant to understanding why listeners perceive certain sounds as the same.
Every consonant in the IPA is described using three parameters:
Voicing: voiced (vocal cords vibrate) or voiceless (they do not).
Place of articulation: where the airstream is obstructed. The main places, front to back:
Bilabial (both lips): /p/, /b/, /m/
Labiodental (lower lip + upper teeth): /f/, /v/
Dental (tongue tip + teeth): /θ/, /ð/
Alveolar (tongue tip + alveolar ridge): /t/, /d/, /s/, /z/, /n/, /l/, /r/
Palato-alveolar / post-alveolar: /ʃ/, /ʒ/, /tʃ/, /dʒ/
Palatal: /j/
Velar (back of tongue + soft palate): /k/, /g/, /ŋ/
Glottal (vocal cords themselves): /h/, /ʔ/
Manner of articulation: how the airstream is modified:
Stop/plosive: complete closure then release (/p/, /b/, /t/, /d/, /k/, /g/)
Fricative: narrow opening, turbulent airflow (/f/, /v/, /s/, /z/, /ʃ/, /ʒ/, /θ/, /ð/, /h/)
Affricate: stop followed immediately by a fricative (/tʃ/, /dʒ/)
Nasal: air flows through the nose (/m/, /n/, /ŋ/)
Approximant/liquid/glide: little obstruction (/l/, /r/, /w/, /j/)
The conventional order for describing a consonant is: voicing, place, manner. For example, /b/ is a "voiced bilabial stop."
Vowels are described by three parameters:
Height (tongue position, vertical): high (close), mid, low (open)
Backness (tongue position, horizontal): front, central, back
Lip rounding: rounded or unrounded
English vowels are plotted on a vowel quadrilateral (the vowel chart). Front vowels in English are unrounded; back vowels tend to be rounded. The schwa /ə/ sits at the centre and is the most common vowel in unstressed syllables.
The International Phonetic Alphabet provides one symbol per sound. Two key notation conventions:
Square brackets [ ] indicate a phonetic (narrow) transcription, capturing exact pronunciation including allophonic detail.
Slashes / / indicate a phonemic (broad) transcription, capturing only the contrastive sounds.
Example: "spin" is phonemically /spɪn/ and phonetically [spɪn] (with an unaspirated [p]), while "pin" is /pɪn/ but phonetically [pʰɪn] (with aspiration).
The central question in phonology is: which sound differences are contrastive (change meaning) and which are non-contrastive (predictable variants)?
Contrastive sounds = separate phonemes.
Non-contrastive variants = allophones of the same phoneme.
The primary test is the minimal pair test. If two words differ by a single sound in the same position and have different meanings, those two sounds are distinct phonemes. Examples in English:
/p/ vs /b/: "pat" vs "bat"
/s/ vs /ʃ/: "sip" vs "ship"
/iː/ vs /ɪ/: "beat" vs "bit"
Complementary distribution: two sounds never appear in the same environment. This is strong evidence they are allophones of one phoneme. Classic example: aspirated [pʰ] occurs at the start of a stressed syllable ("pin" [pʰɪn]), unaspirated [p] occurs after /s/ ("spin" [spɪn]). They share the phoneme /p/.
Free variation: two sounds can substitute for each other in the same environment without changing meaning. Some speakers release final stops, others do not ("cat" may end with an audible [t] or an unreleased [t̚]).
Phonological rules describe systematic patterns that map phonemes to their allophones in particular environments. They are written in the format:
A → B / C __ D
Read as: "A becomes B when it occurs after C and before D."
Common English phonological rules:
Aspiration rule: voiceless stops become aspirated at the beginning of a stressed syllable.
Vowel nasalisation: vowels become nasalised before a nasal consonant (e.g. "can" [kæ̃n]).
Flapping: /t/ and /d/ become a flap [ɾ] between vowels in American English (e.g. "butter" [bʌɾər]).
Vowel lengthening: vowels are longer before voiced consonants than before voiceless ones.
Phonologists describe phonemes not as indivisible units but as bundles of binary features. Each feature captures a phonetic property:
[+/- voice]: whether vocal cords vibrate
[+/- nasal]: whether air flows through the nose
[+/- continuant]: whether air flows continuously (fricatives = [+continuant]; stops = [-continuant])
[+/- anterior]: whether the sound is produced in front of the palato-alveolar region
Distinctive features allow linguists to state phonological rules more economically. Instead of listing every affected sound, a rule can target a natural class defined by shared features.
A syllable consists of:
Onset: consonant(s) before the vowel (optional in English)
Nucleus: the vowel (obligatory)
Coda: consonant(s) after the vowel (optional in English)
The nucleus + coda together form the rhyme (sometimes spelled "rime"). English allows complex onsets (e.g. /str/ in "strong") and complex codas (e.g. /ŋkθs/ in "strengths"), but the combinations follow phonotactic constraints. For instance, English onsets never begin with /ŋ/.
Feature | Phonetics | Phonology |
|---|---|---|
Focus | Physical properties of sounds | Function of sounds in a language |
Scope | Universal (all human languages) | Language-specific |
Unit of analysis | Phone [ ] | Phoneme / / |
Notation | Square brackets [p], [pʰ] | Slashes /p/ |
Approach | Concrete, measurable | Abstract, systematic |
Key question | How are sounds produced and perceived? | Which sound contrasts carry meaning? |
Branches | Articulatory, acoustic, auditory | Segmental, suprasegmental |
The two fields are complementary. Phonetics provides the raw data (the sounds that exist), and phonology provides the analysis (how a language selects and organises those sounds). A phonologist needs phonetic training to identify the sounds, and a phonetician benefits from phonological analysis to know which distinctions matter.
Practical example: the sounds [l] (clear L, as in "lip") and [ɫ] (dark L, as in "full") are phonetically distinct. Phonological analysis shows they are in complementary distribution in English: clear L before vowels, dark L before consonants and at word end. They are therefore allophones of the single phoneme /l/.
"Phonetics and phonology are the same thing." They are not. Phonetics is about the physical sounds themselves; phonology is about how a language organises those sounds into a system. Confusing the two is one of the most common errors on exams.
"A letter equals a sound." English spelling is notoriously inconsistent. The letter "c" can be /k/ ("cat") or /s/ ("city"). The combination "ough" maps to at least six different pronunciations. Always work from IPA symbols, not spelling.
"Aspiration changes meaning in English." It does not. [pʰ] and [p] are allophones of /p/ in English. In some other languages (e.g. Thai, Hindi), aspiration is phonemic, meaning the aspirated and unaspirated versions are separate phonemes.
"Phonological rules are exceptions or irregularities." The opposite is true. Phonological rules describe the regular, systematic, predictable patterns in a language's sound system. What they capture is the norm, not the exception.
⚠️ Be able to describe any English consonant using the three-part label (voicing + place + manner). This is a near-certain exam question.
⚠️ Know the difference between phonemic / / and phonetic [ ] transcription, and when to use each.
⚠️ The minimal pair test is the standard exam method for proving two sounds are separate phonemes. Be ready to supply your own examples.
⚠️ Complementary distribution is tested frequently. Be prepared to look at data from an unfamiliar language, identify which sounds appear in which environments, and determine whether they are allophones or separate phonemes.
⚠️ The aspiration rule is a favourite exam example because it illustrates allophonic variation clearly. Know the environments and be able to write the rule.
⚠️ Syllable structure (onset, nucleus, coda, rhyme) appears on most exams. Be able to break a word into its syllable components.
True or False: Phonology studies the physical production of speech sounds. (False, that is phonetics.)
Fill in the blank: Two words that differ in exactly one phoneme and have different meanings form a ________. (minimal pair)
True or False: [pʰ] and [p] are separate phonemes in English. (False, they are allophones of /p/.)
Fill in the blank: The three parameters used to describe consonants are voicing, ________ of articulation, and ________ of articulation. (place, manner)
True or False: If two sounds are in complementary distribution, they are allophones of the same phoneme. (True.)
Q: Describe the consonant /d/ using the three standard parameters.
A: /d/ is a voiced alveolar stop.
Q: What evidence would you use to argue that /s/ and /z/ are separate phonemes in English?
A: Provide a minimal pair, e.g. "sip" /sɪp/ vs "zip" /zɪp/. The words differ only in /s/ vs /z/ and have different meanings, proving these are distinct phonemes.
Q: Explain why [pʰ] (aspirated) and [p] (unaspirated) are not separate phonemes in English.
A: They are in complementary distribution. [pʰ] appears at the start of a stressed syllable (e.g. "pin"), while [p] appears after /s/ (e.g. "spin") or in unstressed positions. No minimal pair can be found where swapping [pʰ] for [p] changes the meaning. They are allophones of /p/.
Q: Write the phonological rule for English aspiration.
A: Voiceless stops → aspirated / #__ V[+stress] (voiceless stops become aspirated when they occur word-initially or syllable-initially before a stressed vowel).
Q: Identify the onset, nucleus and coda of the word "strengths" /strɛŋkθs/.
A: Onset: /str/. Nucleus: /ɛ/. Coda: /ŋkθs/.
Q: A language has two sounds, [x] and [y]. [x] occurs only before front vowels and [y] occurs only before back vowels. Are they separate phonemes or allophones? What is your evidence?
A: They are allophones of the same phoneme. The evidence is complementary distribution: [x] and [y] never occur in the same environment, so their distribution is predictable from the context.
Phonetics and phonology feed directly into morphology: understanding how sounds change at morpheme boundaries (e.g. the plural "-s" is pronounced /s/, /z/ or /ɪz/ depending on the preceding phoneme) requires phonological analysis. They also connect to semantics and pragmatics through suprasegmental features: intonation patterns can change a statement into a question or signal sarcasm, which is a pragmatic function carried by phonological means.
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