Consonant

In articulatory phonetics, a consonant is a type of speech sound made when we block or partly block the airflow in our vocal tract. Unlike vowels, consonants are created by closing or narrowing parts of our mouth and throat. For example, we use our lips to make sounds like [p] and [b], our front tongue for [t] and [d], and the back of the tongue for [k] and [g]. Some consonants, like [f], [v], [s], and [z], are made by forcing air through a narrow space, called fricatives. Others, like [m] and [n], let air flow through the nose, called nasals.

Most consonants around the world are made using air pushed from our lungs, which are called pulmonic sounds. There are some special consonants, though, made in other ways, like ejectives, implosives, and clicks, but these are rare.

Because there are many more consonant sounds than letters in any alphabet, linguists created the International Phonetic Alphabet (IPA). This system gives each consonant sound its own special symbol so there is no confusion. The English alphabet doesn’t have enough letters for all English consonant sounds, so we use combinations of letters, called digraphs, like ⟨ch⟩, ⟨sh⟩, ⟨th⟩, and ⟨ng⟩. For instance, the ⟨th⟩ sound in “this” is different from the ⟨th⟩ sound in “thin” — in the IPA, these are written as [ð] and [θ], respectively.

Etymology

The word consonant comes from the Latin word cōnsonant-, meaning 'sounding-together'. This Latin term was based on a Greek word, σύμφωνον, which also means 'sounding-together'.

A Greek teacher named Dionysius Thrax described consonants as sounds that can only be said with a vowel in Greek. He split them into two groups: sounds that flow out, called continuants, and sounds that stop, called plosives.

This idea doesn’t work for all languages. For example, in some languages like the Salishan languages, including Nuxalk, you can make plosive sounds without needing a vowel.

Consonant sounds and consonant letters

The word consonant can mean both a special sound we make when we speak and the letters we use to write those sounds. In English, letters such as B, C, D, F, G, J, K, L, M, N, P, Q, S, T, V, X, and Z are called consonants. Sometimes letters like H, R, W, and Y can act as consonants or vowels, depending on the word.

This article focuses on consonant sounds, no matter how they are written.

Consonants versus vowels

Consonants and vowels are different parts of a sound group called a syllable. The loudest part, called the nucleus, is usually a vowel. The parts before and after, called the onset and coda, are usually consonants. For example, in the word "cat," the vowel "a" is the nucleus, and the consonants "c" and "t" are the onset and coda.

Some sounds are tricky to classify. In English, the "y" in "yes" acts like a consonant but is made like a vowel. Also, some consonants can act as the nucleus of a syllable, like the "r" in "church." Languages such as Mandarin and Czech use certain sounds as nuclei too.

Each consonant has special features, like how air escapes when we say it, where in the mouth we make the sound, and whether our voice box vibrates. These features help us understand and describe different consonants.

Examples

The Ubykh language had only a few vowels but many consonants—84 of them! Another language, Taa, can have even more consonants, up to 164, depending on how you look at it. Not all languages use the same consonants. For example, many Australian languages do not use fricatives, which are sounds made by forcing air through a narrow channel. Also, some languages do not use certain sounds like /b/, /d/, or /g/, though they might still make these sounds in speech.

Most languages have some common consonants, like /s/, and usually include a liquid consonant such as /l/. The sounds /w/ and nasals like /m/ and /n/ are also found in many languages. However, a few languages, like Rotokas, have very few consonants—only six. Some languages, such as Arabic, do not use the sound /p/, and others, like Mohawk, lack both /p/ and /m/. The Wichita language and some West African languages, like Ijo, do not use /n/ as a main sound but might use it in other ways. A few languages even lack common nasals entirely. Despite these differences, most languages have at least one velar consonant, such as /k/, though some have similar sounds instead.