In an alphabetic writing system, a silent letter is a letter that, in a particular word, does not correspond to any sound in the word's pronunciation. In linguistics, a silent letter is often symbolised with a null sign , which resembles the Scandinavian letter Ø. A null or zero is an unpronounced or unwritten segment.
English
One of the noted difficulties of English spelling is a high number of silent letters. Edward Carney distinguishes different kinds of "silent" letters, which present differing degrees of difficulty to readers. Auxiliary letters which, with another letter, constitute digraphs; i.e., two letters combined which represent a single phoneme. These may further be categorized as: "Exocentric" digraphs, where the sound of the digraph is different from that of either of its constituent letters. These are rarely considered "silent". Examples: Where the phoneme has no standard single-letter representation, as with consonants for as in sing, for as in thin or as in then, or diphthongs in out or in point. These are the default spellings for the relevant sounds and present no special difficulty for readers or writers. Where standard single-letter representation uses another letter, as with in enough or in physical instead of . These may be considered irregular for writers, but less difficult for readers. "Endocentric" digraphs, where the sound of the digraph is the same as that of one of its constituent letters. These include: Most double consonants, as in clubbed; though not geminate consonants, as in misspell. Doubling due to suffixation or inflection is regular; otherwise, it may present difficulty to writers (e.g., accommodate is often misspelled), but not to readers. Many vowel digraphs, as , , in leave (cf. accede), achieve, eulogy (cf. utopia). The discontiguous digraphs, whose second element is "magic e"; e.g., in rate (cf. rat), in fine (cf. fin). This is the regular way to represent "long" vowels in the last syllable of a morpheme. Others, such as (which is in effect the "doubled" form of ), as in guard, vogue; as in bread, heavy, etc.; , as in aerial, oedipal. These may be difficult for writers and sometimes also for readers. Dummy letters with no relation to neighboring letters and no correspondence in pronunciation: Some are inert letters, which are sounded in a cognate word; e.g., in damn (cf. damnation); in phlegm (cf. phlegmatic); the second in practically (cf. practical); in ballet (cf. balletic); in subtle (cf. subtility). If the cognate is obvious, it may aid writers in spelling, but mislead readers in pronunciation. The rest are empty letters, which never have a sound; e.g., in doubt, in honor, in answer, in Sarah, in island. These may present the greatest difficulty to writers and often to readers, as well.
The distinction between "endocentric" digraphs and empty letters is somewhat arbitrary. For example, in such words as little and bottle, one might view as an "endocentric" digraph for , or view as an empty letter; similarly, with or in buy and build.
Not all silent letters are completely redundant: Silent letters can distinguish between homophones; e.g., in/inn; be/bee; lent/leant. This is an aid to readers already familiar with both words. Silent letters may give an insight into the meaning or origin of a word; e.g., vineyard suggests vines more than the phonetic *vinyard would. Silent letters may help the reader to stress the correct syllable (compare physics to physiques). The final in giraffe gives a clue to the second-syllable stress, where *giraf might suggest initial-stress.
Silent letters arise in several ways: Sound changes occurring without a spelling change. The digraph was pronounced in Middle English in such words as light. Sound distinctions from foreign languages may be lost, as with the distinction between smooth rho () and roughly aspirated rho () in Ancient Greek, represented by and in Latin, but merged to the same in English. Clusters of consonants may be simplified, producing silent letters; e.g., silent in asthma, silent in Christmas (in conservative RP, it is pronounced , as opposed to in all other dialects). Similarly, with alien clusters, such as Greek initial in psychology and in mnemonic, and the much rarer clusters in chthonic and phthalate. Compound words are often simplified in pronunciation, while their spelling remains the same. For example, cupboard and breakfast were once pronounced as written, but were then simplified over time. The words forehead and waistcoat have largely reverted to their spelling pronunciations, but were once pronounced *forrid and *weskit, respectively. Occasionally, spurious letters are consciously inserted in spelling to reflect etymology (real or imagined). The in debt and doubt (from French ) was inserted to match Latin cognates like debit and dubitable. A silent was inserted in isle (Norman French , Old French , from Latin ; cognate to isolate) and then extended to the Germanic word island since they were mistakenly thought to be related. Same thing happened with ptarmigan, with a silent , being thought it was related to the Greek word ('wing').
Since accent and pronunciation differ, letters may be silent for some speakers, but not others. In non-rhotic accents, is silent in such words as hard, feathered; in h-dropping accents, is silent. A speaker may or may not pronounce in often, the first in Antarctic, in sandwich, etc.
Differences between British English and American English
Pronunciation
In the US, the h in herb is silent (an herb), but in the UK, it is pronounced (a herb). The same is true for the l in solder.
In parts of the UK, the a in dictionary and secretary is silent, but in the US, it is pronounced.
Spelling
In US spellings, silent letters are sometimes omitted (e.g., acknowledgment / UK acknowledgement, ax / UK axe, catalog / UK catalogue, program / UK programme outside computer contexts), but not always (e.g., dialogue is the standard spelling in the US and the UK; dialog is regarded as a US variant; the spelling axe is also often used in the US). In most words, silent letters are written in both styles (e.g., debt, guard, house).
Other Germanic languages
Danish The Danish language has different letters that can be silent:
The letter is silent in the preposition af ('by, of, from, off, with, out of'). The letter is silent in the conjunction og ('and') and adverb også ('also'). The letter is silent in most dialects if followed by , as in the pronouns hvad ('what'), hvem ('who'), hvor ('where').:da:Stumt bogstav The letter is silent at the end of words if preceded by , as in the pronoun selv ('self') and adjective halv ('half'). The letter is usually (but not necessarily) silent if preceded by a consonant, as in en mand ('a man') and blind ('blind'). Many words ending in are pronounced with a stød, but it is still considered a silent letter.
Faroese
The Faroese language has two silent letters.
The letter is almost always silent. It is rendered in orthography for historical reasons (e.g., 'father' , cf. Old Norse ). In some cases, however, the letter is pronounced , as in 'the weather' .
The letter (i.e. continuant of Old Norse ) is usually silent between vowels or when following a vowel before a pause (e.g., 'day' , cf. Old Norse ; 'I' , cf. Old Norse ). Use of the silent letter in Faroese is the same as for the letter edd; it is written for historical reasons as Faroese orthography was based on normalised spelling of Old Norse and Icelandic language.
Both Faroese silent letters and are replaced by a hiatus glide consonant (, or ) when followed by another (unstressed) vowel.
German In German, silent letters are rare apart from word-internal (following a vowel) and the in the digraph .
Silent h is used in German to indicate vowel length or hiatus. This h is almost regularly added at the end of inflectable word stems, e.g. Kuh (cow), Stroh (straw), drehen (to turn, stem dreh-). There is only a fairly small number of exceptions to this, mostly nouns in -ee or -ie (see below), apart from isolated cases such as säen (to sow).
Otherwise silent h may be written before the letters l, m, n, r as in nehmen (to take), Stuhl (chair), Zahn (tooth). This latter use is highly irregular, however, and there are just as many words where the h is missing.
Historically, this use of silent h goes back to the Middle High German consonant , which became silent in words like sehen (to see), zehn (ten). By analogy it was then also used in words that had no such h in Middle High German. The majority of silent h in modern German are analogical rather than etymological.
The long i-sound is usually written , with a silent , as in viel (much), spielen (to play), Wien ('Vienna'), and hundreds of other words.
In native German words this spelling is fairly unambiguous. Some words of foreign origin also behave like native words; e.g., Kurier, Papier, Turnier and all verbs ending in (e.g. appellieren, organisieren). In other foreign words, however, the after may be pronounced (e.g., Ambiente, Hygiene, Klient), or names like Daniela, Gabriel, and Triest.
Words ending in can be particularly tricky to learners: There are generally two possibilities:
When the final is stressed, it represents long as in Zeremonie . Some other words with pronounced this way include Akademie, Allergie, Amnesie, Amnestie, Apathie, Artillerie, Batterie, Blasphemie, Chemie, Chirurgie, Demokratie, Energie, Epidemie, -gamie, Garantie, Genie, Geometrie, -grafie/-graphie, Harmonie, Hysterie, Infanterie, Ironie, Kavallerie, Kompanie, Kopie, -logie, Liturgie, Magie, Manie, Marie, Melodie, Monotonie, Nostalgie, Orthopädie, Partie, Phantasie, Philosophie, Poesie, Psychiatrie, Rhapsodie, Sinfonie, -skopie, Theorie, Therapie, and Utopie. When the preceding vowel is stressed, represents the separate vowels as in Folie . Some other words with pronounced this way include Akazie, Aktie, Amalie, Begonie, Emilie, Familie, Folie, Geranie, Grazie, Hortensie, Hostie, Immobilie, Kastanie, Komödie, Kurie, Lilie, Linie, Orgie, Otilie, Pinie, Serie, Studie, Tragödie, and Zäzilie. In female names, there is a third category of words stressed on the antepenult, where also represents ; e.g., Amelie, Leonie, Nathalie, Rosalie, Stefanie, Valerie (all stressed on the first syllable).
A special case arises when the after is a grammatical ending; in this case, it is always pronounced. Therefore, Zeremonie becomes Zeremonien in the plural, and the same is true of all other nouns in group 1 above. The noun Knie is pronounced when it is singular, but usually when it is plural. Spermien is plural of Spermium, hence also with a pronounced . Country names in -ien can also be joined to this group: Australien, Brasilien, Indien, Kroatien, Serbien, Slowenien.
Other letters Other silent letters occur mainly in borrowings from French and other modern languages; e.g., Porträt (portrait), Korps (corps).
Informally, the letter may be silent in function words like ist (is), jetzt (now), nicht (not), and otherwise in clusters like Gedächtnis (memory), Kunststück (piece of art). These t are commonly silent in everyday speech, but will be retained in careful, formal parlance.
Two other cases of potentially silent letters are regionally restricted: Speakers from northern and central Germany commonly do not pronounce the in stem-initial and in , e.g., pflegen, kämpfen. In various regions, may be silent when following in the syllable coda, e.g. Fahrt, Karte. Compare German phonology.
Romance languages
Catalan
In Standard Catalan, the letter is silent in several words (e.g. is pronounced as ).
Valencian
In the suffix and their derivatives, the letter is completely silent. (e.g. is pronounced as , compare Standard Catalan )
French