International Phonetic Alphabet (IPA)

Why the IPA exists

Every writing system was designed for a particular language at a particular moment, and most have drifted ever since. English spelling fixes pronunciations from before the Great Vowel Shift. French keeps consonants nobody pronounces. Mandarin pinyin uses ⟨q⟩ for [tɕʰ] and ⟨x⟩ for [ɕ]. The same letter ⟨c⟩ is /k/ in Italian, /s/ in French before e, /tʃ/ in English cello, /ts/ in German.

This is fine for native readers, who memorize the conventions. It is hopeless for anything cross-linguistic: comparing dialects, teaching pronunciation, documenting an undocumented language, training speech recognition. Linguists need a notation that decouples sound from spelling, and assigns a stable symbol to every distinct articulation.

The IPA was that project, begun by a group of French and English language teachers led by Paul Passy in 1886. Their stated principle: one letter, one sound. The first chart, published in 1888 in the journal Le Maître phonétique, has been revised eleven times since.

How the chart is organized

The IPA is not a list. It is a grid that encodes how each sound is produced.

• Pulmonic consonants sit in a table whose rows are manner of articulation (the kind of obstruction: stop, nasal, trill, tap, fricative, approximant, lateral) and whose columns are place of articulation (where the obstruction happens: bilabial, labiodental, dental, alveolar, postalveolar, retroflex, palatal, velar, uvular, pharyngeal, glottal).
• Voicing is shown by paired symbols within each cell: voiceless on the left, voiced on the right. Where only one symbol appears, only one voicing is attested.
• Non-pulmonic consonants — clicks, ejectives, implosives — sit in a separate table because they are made with non-lung airstreams.
• Vowels are plotted on a trapezoid that abstracts the oral cavity: high-low corresponds to tongue height, front-back to tongue advancement. Pairs are shown unrounded then rounded.
• Diacritics modify the basic symbols: nasalization [˜], aspiration [ʰ], length [ː], dental [t̪], retracted [a̠], etc.
• Suprasegmentals mark stress (ˈ primary, ˌ secondary), syllable boundaries (.), tone, and intonation.

A slice of the consonant chart

The consonant grid is large. A representative slice (pulmonic stops, nasals, fricatives) shows the structure clearly.

Manner	Bilabial	Labiodental	Alveolar	Postalveolar	Velar	Glottal
Stop (voiceless / voiced)	p / b	—	t / d	—	k / g	ʔ / —
Nasal	m	ɱ	n	—	ŋ	—
Fricative (voiceless / voiced)	ɸ / β	f / v	s / z	ʃ / ʒ	x / ɣ	h / ɦ
Approximant	—	ʋ	ɹ	—	ɰ	—
Lateral approximant	—	—	l	—	ʟ	—
Trill	ʙ	—	r	—	—	—

Empty cells without explanation represent unattested but possible articulations. Greyed-out cells (in the published chart) represent articulations judged impossible — for instance, a velar trill, because the back of the tongue cannot vibrate freely.

The vowel trapezoid

Vowels are continuous in articulatory space, so the chart uses a four-corner abstraction with cardinal reference points.

	Front	Central	Back
Close (high)	i (unrounded) / y (rounded)	ɨ / ʉ	ɯ / u
Close-mid	e / ø	ɘ / ɵ	ɤ / o
Mid	—	ə (schwa)	—
Open-mid	ɛ / œ	ɜ / ɞ	ʌ / ɔ
Open (low)	a / ɶ	ä	ɑ / ɒ

Daniel Jones's eight cardinal vowels — i, e, ɛ, a, ɑ, ɔ, o, u — anchor the system. Real-language vowels are described by where they sit on this lattice. American English /æ/ is between cardinal /ɛ/ and /a/. French /y/ is the rounded counterpart of /i/; German über's vowel is the same /yː/.

The same word in IPA across languages

To see how IPA flattens orthographic noise, compare the same concept written in five languages and then in IPA.

Language	Spelling	IPA (broad)	Notes
English	night	/naɪt/	Diphthong /aɪ/, silent ⟨gh⟩
German	Nacht	/naxt/	⟨ch⟩ is /x/ after a back vowel
French	nuit	/nɥi/	Labiopalatal approximant /ɥ/
Spanish	noche	/ˈnotʃe/	Trochaic stress, /tʃ/ for ⟨ch⟩
Mandarin	夜 yè	/jɛ˥˩/	Falling tone written with tone letters

Five different orthographies become five precise sound-strings, comparable directly. This is why every introductory linguistics course teaches the IPA before any other tool: it is the lingua franca of phonetics and phonology.

Worked example: transcribing "photograph"

Take the English word photograph. Spelling: nine letters, two of them silent depending on accent. IPA tells us what is actually pronounced.

1. Identify phonemes. Eight: /f/, /oʊ/, /t/, /ə/, /g/, /ɹ/, /æ/, /f/. Broad transcription: /ˈfoʊtəˌgɹæf/.
2. Mark stress. Primary on the first syllable, secondary on the third: ˈfoʊ-tə-ˌgɹæf.
3. Add allophonic detail (narrow). The first /f/ is plain [f]; the /t/ is unaspirated because it is in an unstressed syllable, surfacing as [ɾ] in American English: [ˈfoʊɾəˌgɹæf]. The vowel before /n/ would be nasalized — there is no /n/ here, so no nasalization.
4. Compare to the related word photography. Stress shifts: /fəˈtɑgɹəfi/. The same lexical root surfaces with completely different vowels because English vowel reduction is stress-driven. Only IPA captures this — orthography hides it.

Competing notations and theoretical debates

The IPA is not the only phonetic alphabet, and within it there are choices that have been argued for over a century.

System	Origin / use	Strengths	Weaknesses
IPA	International Phonetic Association, 1888	Universal, articulatorily organized, peer-maintained	Many symbols not on standard keyboards; learners struggle with diacritics
Americanist Phonetic Notation (APA)	US fieldwork tradition (Boas, Sapir)	Fewer special characters, easier on typewriters	Inconsistent across authors; ⟨š⟩ for /ʃ/, ⟨č⟩ for /tʃ/ — only partially overlaps with IPA
SAMPA / X-SAMPA	1989, ASCII-only IPA	Typeable on any keyboard; used in speech tech	Read-only mapping to IPA; not standalone
Pinyin (Mandarin)	1958, official Chinese romanization	Optimized for one language; simple	Not phonetic outside Mandarin; ⟨q⟩, ⟨x⟩, ⟨zh⟩ misleading
Dictionary respelling	Webster, Oxford and similar	Readable to non-linguists	English-specific; does not transcribe other languages
Praat / acoustic feature notation	Lab phonetics	Tied to measurable parameters (F1, F2, VOT)	Not human-readable for dictionary use

Internal IPA debates include: whether to keep separate symbols for sounds that turn out to be allophonic in nearly all languages (the labiodental flap [ⱱ] was added only in 2005); whether to standardize one symbol per articulation or per phonologically distinct category; how finely the vowel space should be subdivided. The Association votes on changes; revisions are conservative.

Variants and applications

• extIPA. Extensions to the IPA for Disordered Speech, used by speech-language pathologists; adds symbols for sounds that arise in clinical populations (e.g., labioalveolar contact).
• VoQS. Voice Quality Symbols, a parallel set for voice quality (creaky, breathy, harsh, whispery).
• ToBI. Tones and Break Indices, for prosodic transcription of intonation; commonly used alongside IPA.
• SAMPA / X-SAMPA. ASCII-mapped versions of the IPA, designed for speech-recognition databases and email-era linguistics; X-SAMPA is the more complete.
• IPA-Unicode. Most IPA symbols are encoded in Unicode (block U+0250–U+02AF, with extensions). Modern linguistic work uses Unicode IPA fonts like Doulos SIL, Charis SIL, or system fonts.

Common pitfalls

• Confusing slashes and brackets. /p/ is a phoneme; [p] is a phonetic realization. The convention matters; mixing them obscures whether you are claiming contrast or detail.
• Treating IPA as a pronunciation guide for English speakers. ⟨a⟩ in IPA is a low front unrounded vowel, not the English ⟨a⟩ in cat. ⟨e⟩ is mid-front, not the diphthong of English day. Read every symbol as IPA, not as your native orthography.
• Forgetting the diacritics. [t] and [tʰ] differ; so do [a] and [ã]; so do [s] and [s̪]. Narrow transcription is the diacritics.
• Using IPA for orthographic respelling. Some popular guides write English night as [nɪɡʰt]. This is incorrect: it is /naɪt/.
• Assuming the chart is closed. The IPA evolves; recent changes added the labiodental flap (2005) and revised the chart layout (2020). Always check the latest version.
• Confusing tonemes and tone letters. Tone is suprasegmental; the five tone letters (˥ ˦ ˧ ˨ ˩) are stacked to indicate contour, not appended like vowel diacritics.