Consonant Sounds and Letters in English

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A consonant is a speech sound that's not a vowel. The sound of a consonant is produced by a partial or complete obstruction of the airstream by a constriction of the speech organs. In writing, a consonant is any letter of the alphabet except A, E, I, O, U, and sometimes Y.

Consonants vs. Vowels 

When consonants and vowels are put together, they form syllables, which are the basic units of pronunciation.

Syllables, in turn, are the foundation of words in English grammar. Phonetically, however, consonants are much more variable.

In his book "Letter Perfect," the author David Sacks described the difference this way: "Whereas vowels are pronounced from the vocal cords with minimal shaping of expelled breath, consonant sounds are created through obstruction or channeling of the breath by the lips, teeth, tongue, throat, or nasal passage...Some consonants, like B, involve the vocal cords; others don't. Some, like R or W, flow the breath in a way that steers them relatively close to being vowels."

Consonant Blends and Digraphs

When two or more consonant sounds are pronounced in succession without an intervening vowel (as in the words "dream" and "bursts"), the group is called a consonant blend or consonant cluster. In a consonant blend, the sound of each individual letter can be heard.

By contrast, in a consonant digraph, two successive letters represent a single sound.

Common digraphs include G and H, which together mimic the sound of F (as in the word "enough"), and the letters P and H, which also sound like an F (as in "phone").

Silent Consonants

In a number of cases in English, consonant letters can be silent, such as the letter B following M (as in the word "dumb"), the letter K before N ("know"), and the letters B and P before T ("debt" and "receipt").

 When a double consonant appears in a word, usually only one of the two consonants is sounded (as in "ball" or "summer").

Stop Consonants

Consonants can also serve as a means of bracketing a vowel, stopping their sound. They are called stop consonants because the air in the vocal tract is completely stopped at some point, usually by the tongue, lips, and/or teeth. The letters B, D, and G are the most frequently used stops, though P, T, and K also can serve the same function. Words that contain stop consonants include "bib" and "kit."

Consonance

Broadly, consonance is the repetition of consonant sounds; more specifically, consonance is the repetition of the final consonant sounds of accented syllables or important words. Consonance is frequently used in poetry, song lyrics, and prose when the writer wants to create a sense of rhythm. One well-known example of this literary device is the tongue twister, "She sells seashells by the seashore."

Using 'A' and 'An' 

In general, words that begin with vowels should be introduced by the indefinite article "an," while words that start with consonants are set off with an "a" instead. However, when the consonants at the beginning of the word produce a vowel sound, you would use the article "an" instead (an honor, a house).