Vowels, Consonants and Phonetic Basics

English speech sounds are broadly classified into vowels and consonants. Understanding the distinction between them provides a foundation for learning English pronunciation.

A vowel is produced when air flows through the vocal tract without a complete closure or significant obstruction. Vowels generally form the central part of syllables. English vowel sounds include relatively short and long qualities as well as changing vowel sounds known as diphthongs.

Vowels can be described according to the position of the tongue, the height of the tongue, the position of the lips, and the movement of the vocal organs. English spelling uses only a small number of vowel letters, but these letters can represent many different vowel sounds. For example, the letter a has different pronunciations in cat, cake, father, and about.

A consonant involves some degree of obstruction or narrowing of the airflow. Consonants can be classified according to place of articulation, manner of articulation, and voicing.

Place of articulation describes where the sound is produced. Examples include bilabial sounds produced with both lips, such as /p/, /b/, and /m/; labiodental sounds involving the lips and teeth, such as /f/ and /v/; and alveolar sounds produced near the alveolar ridge, such as /t/, /d/, /s/, and /z/.

Manner of articulation describes how the airflow is controlled. Stops or plosives involve complete closure followed by release, as in /p/, /b/, /t/, /d/, /k/, and /g/. Fricatives involve a narrow passage through which air creates friction, as in /f/, /v/, /s/, and /z/. Other categories include affricates, nasals, approximants, and lateral sounds.

Voicing refers to whether the vocal cords vibrate during the production of a sound. /s/ is normally voiceless, while /z/ is voiced. Similarly, /p/ and /b/ form a voiceless–voiced pair.

English syllables are built around a nucleus, normally a vowel sound. A syllable may also contain an onset before the nucleus and a coda after it. For example, cat contains /k/ as its onset, /æ/ as its nucleus, and /t/ as its coda.

English also uses diphthongs, where the vowel quality moves from one position toward another within a syllable, as in the vowel sounds of boy, day, and now.

For learners, the most important principle is that letters and sounds are not identical concepts. A letter is a written symbol; a sound is a unit of spoken language. One letter can represent different sounds, and the same sound can be represented by different letters or combinations of letters.