What is the International Phonetic Alphabet? How to read it

The International Phonetic Alphabet, or IPA, is a set of symbols for writing down how words are pronounced, with one symbol for each distinct speech sound and the same symbol for that sound in every language. It was created by the International Phonetic Association, founded in Paris in 1886. Dictionaries, language teachers, speech therapists and singers use it because ordinary spelling, English spelling above all, is a poor guide to sound.

In short

• Each IPA symbol stands for one sound, and each sound has one symbol, so a transcription can be read the same way by anyone who knows the chart.
• Consonants are arranged by where in the mouth the sound is made and how the air is shaped; vowels by how high and how far forward the tongue is.
• Slashes, /like this/, mark the sounds a language treats as distinct; square brackets, [like this], mark exact pronunciation.

Why does the International Phonetic Alphabet exist?

Because spelling and sound drift apart. In English, the letters ough are pronounced differently in though, through, tough, cough and bough, while the single sound at the start of shoe is spelled sh, s (sugar), ti (nation) and ch (machine). Every language that has been written for a long time has some of this, because pronunciation changes faster than spelling. The note on where the alphabet came from traces how the Latin letters got their sounds in the first place.

A group of language teachers in France, led by Paul Passy, formed the association in 1886 to help teach pronunciation, according to the International Phonetic Association's own history. In 1888 they fixed the values of the letters so that each meant the same sound across languages. They started from the Latin alphabet, added letters borrowed from Greek or reshaped, and put marks called diacritics on them for fine distinctions. The alphabet has been revised many times since; a meeting in Kiel, Germany, in 1989 overhauled it, the last new letter was added in 2005, and the chart's current wording and layout date from 2015. It now has 107 letters for individual sounds, plus diacritics and marks for features such as stress, length and tone, as listed in the overview of the alphabet.

The core principle is simple: one symbol per sound, and one sound per symbol. That lets a linguist write down a language no one has ever spelled, and lets a reader pronounce a word in a language they don't know.

How do you read an IPA transcription?

Most IPA letters for consonants look like ordinary letters and sound the way a reader of European languages would expect: /p/, /b/, /t/, /d/, /k/, /m/, /n/, /s/, /f/, /l/. The rest are learned a few at a time. Here are three English words, read symbol by symbol. Each is given in a British standard, often called Received Pronunciation, and in General American, because dictionaries transcribe the two differently. Neither is more correct; they are two accents.

thought: UK /θɔːt/, US /θɔt/ or /θɑt/

1. θ (Greek theta) is the th sound in thin, made with the tongue between the teeth and no voice. It is a different sound from the th in this, which is written ð.
2. ɔ is an open-mid back rounded vowel: the vowel of British thought, caught or law, lips rounded.
3. ː after a vowel means it is long.
4. t is the ordinary t.
5. In much of North America, thought and cot share a vowel, the open back ɑ, so many American dictionaries give /θɑt/ for those speakers. The English key used by Wikipedia notes that speakers with this merger can simply ignore the difference.

church: UK /tʃɜːtʃ/, US /tʃɝtʃ/

1. tʃ is the ch sound: a t released straight into a sh. Written with two symbols, it counts as one sound, an affricate.
2. ɜ is a mid central vowel, the vowel of nurse or bird, with ː for length in British English, where the r is not pronounced before a consonant.
3. ɝ is the same vowel with r-coloring, the tongue curled or bunched, as most Americans say it.
4. tʃ again at the end. Six letters of spelling, three sounds.

measure: UK /ˈmeʒə/, US /ˈmeʒɚ/

1. ˈ before a syllable marks the main stress: MEA-sure.
2. m is the ordinary m.
3. e is the vowel of dress; many dictionaries write the same vowel ɛ.
4. ʒ (called ezh) is the voiced partner of sh, the sound in the middle of measure, vision and beige. English has no letter of its own for it.
5. ə (schwa) is the weak, unstressed vowel at the end of British measure or the start of about. ɚ is schwa with r-coloring, the American ending.

Slashes mean the transcription shows only the sounds the language treats as different; square brackets show exact detail. The p in pin is breathier than the p in spin. To an English speaker it is one sound, /p/; a phonetician writing exactly would put [pʰɪn] for pin, the small ʰ marking that puff of air.

How is the consonant chart organized?

The chart is a grid, and once its logic is clear, any consonant can be found. The columns are the place of articulation, where in the mouth the air is blocked or narrowed, running from the lips on the left to the throat on the right. The rows are the manner of articulation: how the air is shaped, whether stopped completely, sent through the nose, or squeezed into a hiss. In a cell with two symbols, the left is voiceless and the right is voiced, with the vocal cords vibrating. The full chart is published free by the association on its IPA chart page.

Here is the part of it that covers most English consonants:

	Lips (bilabial)	Lip and teeth (labiodental)	Teeth (dental)	Ridge behind the teeth (alveolar)	Behind the ridge (postalveolar)	Soft palate (velar)	Throat (glottal)
Stop (plosive)	p b			t d		k g	ʔ
Nasal	m			n		ŋ
Fricative		f v	θ ð	s z	ʃ ʒ		h
Approximant				ɹ
Lateral approximant				l

Read it as coordinates. ʃ, the sh in shoe, is a voiceless postalveolar fricative: the air hisses through a gap just behind the ridge of your upper gums. Move the tongue forward to the ridge and you get s; add voice and it becomes z. The ŋ is the sound at the end of sing, a nasal made at the soft palate, which English spells with two letters. The ʔ is the glottal stop in the middle of uh-oh. And ɹ is the English r; the plain letter r in the IPA means a trilled r, as in Spanish perro.

Vowels have their own chart, shaped like a tilted box that maps the space inside the mouth: high vowels such as i (fleece) at the top, low vowels such as a at the bottom, front vowels on the left and back vowels such as u (goose) on the right. Where symbols come in pairs, the right one is said with rounded lips.

Who uses the IPA, and where do you meet it?

Most people meet it in a dictionary. The learner's dictionaries published by Oxford, Cambridge and Merriam-Webster use the IPA, though each makes small choices of its own, such as e or ɛ for the vowel of dress. Language learners use it to hear sounds their own language lacks, and it pairs well with practice spread out over time, as in spaced repetition. Linguists use it to record languages and compare them, the groundwork for tracing language families. Speech therapists use it to note exactly how a child's speech differs from the target, and singers use it to sing in languages they don't speak.

It also has limits. It describes sounds, not meaning, so it can't replace a writing system, and it doesn't capture everything: voice quality, speed and melody need extra marks or none. For tone languages such as Mandarin, the IPA has tone letters, though learners more often use the pinyin marks described in the note on how Chinese characters work. And it is built for human speech in general, the subject of what language is, so the full chart includes clicks, implosives and other sounds that English never uses.

Check yourself

• Without looking back: why can't English spelling tell you how ough is pronounced, and how does the IPA solve that?
• Using the grid, describe ʒ by its place, manner and voicing, and name the English sound that is its voiceless partner.
• What is the difference between /p/ and [pʰ], and why would a dictionary use the first?

Sources

• History of the IPA — International Phonetic Association
• IPA chart — International Phonetic Association, chart revised to 2015, CC BY-SA 4.0
• International Phonetic Alphabet — Wikipedia
• Help: IPA for English — Wikipedia