Consonant: Speech sound that is articulated with complete or partial closure of the vocal tract

A consonant is a speech sound in which the air is at least partly blocked, and any letter which represents this. Consonants may come singily (by themselves) or in clusters (two or more together), but must be connected to a vowel to form a syllable.

Notice that the consonant (C) and vowel (V) notation does not match the letters of English spelling in a one-to-one relationship (e.g. 'th' is one sound), but rather individual sounds.

Words with single consonants include:

• Go (CV), which has one consonant and one vowel in that order
• On (VC), which has one vowel and one consonant in that order
• Ton (CVC), which has a consonant, a vowel, and another consonant in that order

Words with consonant clusters include:

• Pro (CCV), which has two consonants in-a-row and one vowel afterwards
• Old (VCC), which has one vowel and two consonants in-a-row afterwards
• Spree (CCCV), which has three consonants in-a-row and one vowel afterwards
• Arcs (VCCC), which has one vowel and three consonants in-a-row afterwards
• Strengths (CCCVCCCCC), which has three consonants in-a-row, one vowel afterwards, and finally five consonants in a row

Consonants have friction when they are spoken, mostly using the position of the tongue against the lips, teeth and roof of the mouth. b and p are plosives, using the lips to produce a tiny sharp sound. Phonetics texts give more details, with diagrams. Consonants may be voiced or unvoiced. The th in the is voiced, but in breath is not.

• There are 21 consonant letters in English, for 24 consonant sounds in most English accents.^p242 Because of the history of the English language, there is no neat one-to-one relationship between letter and sound. th and ch each stand for a single sound, and x in fox stands for two sounds (ks). All these letters are consonants:

B, C, D, F, G, H, J, K, L, M, N, P, Q, R, S, T, V, W, X, (sometimes Y), and Z. "Y" is often used as a consonant, but it is sometimes used as a vowel. For example, in the word yellow, y is a consonant. But in the word happy, y is a vowel.

• The rest of the letters of the alphabet are called vowels. Vowels are underdone, for there are about 20 vowel sounds in most English accents.^p237 The vowels are:

A, E, I, O, U (and sometimes Y)