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 U+2205 ∅ EMPTY SET. Null is an unpronounced or unwritten segment. The symbol resembles the Scandinavian letter Ø and other symbols.
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.
The distinction between "endocentric" digraphs and empty letters is somewhat arbitrary. For example, in such words as little and bottle, one might view ⟨le⟩ as an "endocentric" digraph for /əl/, or view ⟨e⟩ as an empty letter; similarly, with ⟨bu⟩ or ⟨u⟩ in buy and build.
Since accent and pronunciation differ, letters may be silent for some speakers, but not others. In non-rhotic accents, ⟨r⟩ is silent in such words as hard, feathered; in h-dropping accents, ⟨h⟩ is silent. A speaker may or may not pronounce ⟨t⟩ in often, the first ⟨c⟩ in Antarctic, ⟨d⟩ in sandwich, etc.
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.
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).
The letter ⟨h⟩ is silent in most dialects if followed by ⟨v⟩, as in hvad (‘what’), hvem (‘who’), hvor (‘where’).
The letter ⟨v⟩ is silent at the end of words if preceded by ⟨l⟩, as in selv ('self'), halv ('half').
The letter ⟨d⟩ is usually (but not necessarily) silent if preceded by a consonant, as in en mand (‘a man’), blind (‘blind’). Many words ending in ⟨d⟩ are pronounced with a stød, but it is still considered a silent letter.
The letter edd ⟨ð⟩ is almost always silent. It is rendered in orthography for historical reasons (e.g. faðir 'father' [ˈfɛajɪɹ], cf. Old Norse faðir). In some cases, however, the letter edd is pronounced [ɡ̊], as in veðrið 'the weather' [ˈvɛɡ̊ʐɪ].
The letter ge ⟨g⟩ (i.e. continuant of Old Norse [ɣ]) is usually silent between vowels or when following a vowel before a pause (e.g. dagur 'day' [ˈd̥ɛavʊɹ], cf. Old Norse dagr [ˈdaɣʐ]; eg 'I' [ˈeː], cf. Old Norse ek). Use of the silent letter ge 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.
In German, silent letters are extremely rare and occur usually in loanwords, rather than German words.
In some words of foreign origin, the ⟨e⟩ after ⟨i⟩ is pronounced, e.g. Ambiente, Bakterien (plural of Bakterium), Hygiene, Klient, Spermien (plural of Spermium), but is silent in e.g. Kurier, Papier, Turnier and all the -ieren verbs already mentioned. In Zeremonie, the final ⟨e⟩ is usually silent but always pronounced in its plural form Zeremonien.
Words ending in ⟨-ie⟩ can be somewhat tricky to learners:
For example, the final ⟨e⟩ is pronounced in the words Akazie, Aktie, Aktinie, Begonie, Familie, Folie, Geranie, Grazie, Hortensie, Hostie, Immobilie, Kastanie, Komödie, Kurie, Lilie, Linie, Orgie, Pinie, Serie, Studie, Tragödie,
while it is silent in the words Akademie, Allergie, Amnesie, Amnestie, Apathie, Artillerie, Batterie,Blasphemie, Chemie, Chirurgie, Demokratie, Energie, Epidemie, -gamie, Garantie, Genie, Geometrie, -grafie/-graphie, Harmonie, Hysterie, Infanterie, Ironie, Kavallerie, Knie, Kompanie, Kopie, -logie, Liturgie, Magie, Manie, Melodie, Monotonie, Nostalgie, Orthopädie, Partie, Phantasie, Philantropie, Philatelie, Philosophie, Poesie (but the e after the o is pronounced), Psychiatrie, Rhapsodie, Sinfonie, -skopie, Theorie, Therapie, Utopie.
In the female names Amalie, Emilie, Otilie, Zäzilie, the final e is pronounced, but it is silent in Leonie, Marie (but in compound words such as Marienplatz [a place in Munich], Marienstatue [statue of the Virgin Mary], the e is pronounced; the Virgin Mary is called Maria in German), Nat(h)alie, Rosalie, Rosemarie, Stefanie (or: Stephanie), Valerie.
The e is pronounced in the names Ariel(le), Daniel,Daniela, Gabriel, Gabriel(l)e (in Gabriele, the final e is pronounced), Gabriella, Mariele (the final e is pronounced), Mariella, Muriel,, but it is silent in Dieter, Frieda, Friederich, Siegfried, Siegrid, Sieglinde (the final e is pronounced), Wieland.
In country names ending in -ien , the e is pronounced: Australien, Brasilien, Indien, Kroatien, Serbien, Slowenien. In city names, the pronunciation of e after i varies: In Wien (Vienna), the e is silent, but in Triest, it is pronounced.
A silent h sometimes indicates vowel length, as in Stuhl ('chair'), or a hiatus, as in drehen ('to turn'). That h derives from an old /x/ in some words such as sehen ('to see') zehn ('ten'), but in other words, it has no etymological justification such as gehen ('to go') or mahlen ('to mill').
Silent letters are common in French, including the last letter of most words. Ignoring auxiliary letters that create digraphs (such as ⟨ch⟩, ⟨gn⟩, ⟨ph⟩, ⟨au⟩, ⟨eu⟩, ⟨ei⟩, and ⟨ou⟩, and ⟨m⟩ and ⟨n⟩ as signals for nasalized vowels), they include almost every possible letter except ⟨j⟩ and ⟨v⟩.
Final ⟨e⟩ is silent or at least (in poetry and song) a nearly-silent schwa /ə/; it allows the preservation of a preceding consonant, often allowing the preservation of a grammatical distinction between masculine and feminine forms in writing, e.g., in vert and verte (both ‘green’); the ⟨t⟩ is pronounced in the latter (feminine) but not the former. Furthermore, the schwa can prevent an awkward ending of a word ending in a consonant and a liquid (peuple, sucre).
After ⟨é⟩, ⟨i⟩, or ⟨u⟩, a final ⟨e⟩ is silent. The spelling ⟨eau⟩ is pronounced just the same as that for ⟨au⟩ and is entirely an etymological distinction, so in that context, the ⟨e⟩ is silent.
In most dialects, the letter ⟨h⟩ is almost always silent, except in the digraphs ⟨ch⟩ and ⟨ph⟩. However, in some words, an initial letter ⟨h⟩ marks an audible hiatus that prevents liaison, cf. words starting with an aspirated h. Numerous doubled consonants exist; French does not distinguish doubled consonants from single consonants in pronunciation as Italian does. A marked distinction exists between a single and doubled ⟨s⟩: doubled ⟨ss⟩ is always voiceless [s], while an intervocalic single ⟨s⟩ is voiced [z].
The nasal consonants ⟨m⟩ and ⟨n⟩ when final or preceding a consonant ordinarily nasalize a preceding vowel but are not themselves pronounced (faim, tomber, vin, vendre). Initial and intervocalic ⟨m⟩ and ⟨n⟩, even before a final silent ⟨e⟩, are pronounced: aimer, jaune.
Most final consonants are silent, usual exceptions to be found with the letters ⟨c⟩, ⟨f⟩, ⟨l⟩, and ⟨r⟩ (the English word careful is mnemonic for this set). But even this rule has its exceptions: final ⟨er⟩ is usually pronounced /e/ (=⟨é⟩) rather than the expected /ɛʀ/. Final ⟨l⟩ is silent after ⟨i⟩ even in a diphthong (œil, appareil, travail). Final -ent is silent as a third-person plural verb ending, though it is pronounced in other cases.
Final consonants that might be silent in other contexts (finally or before another consonant) may seem to reappear in pronunciation in liaison: ils ont [ilz‿ɔ̃] "they have", as opposed to ils sont [il sɔ̃] "they are"; liaison is the retention (between words in certain syntactic relationships) of a historical sound otherwise lost, and often has grammatical or lexical significance.
The letter ⟨h⟩ most often marks a ⟨c⟩/⟨g⟩ as hard (velar), as in spaghetti, where it would otherwise be soft (palatal), as in cello, because of a following front vowel (⟨e⟩ or ⟨i⟩). Conversely, a silent ⟨i⟩ marks a ⟨c⟩/⟨g⟩ as soft where it would otherwise be hard because of a following back vowel (⟨a⟩, ⟨a⟩, ⟨o⟩ or ⟨u⟩), as in ciao, Perugia.
Silent ⟨h⟩ is also used in forms of the verb avere ('have') – ho, hai and hanno – to distinguish these from their homophones o ('or'), ai ('to the') and anno ('year'). The letter ⟨h⟩ is also silent at the beginning of words borrowed from other languages, such as hotel.
In the vast majority of cases, Czech pronunciation follows the spelling. There are only four exceptions:
In most present forms of the verb být ("to be"), namely jsem, jsi, jsme, jste and jsou (i.e. all persons but the 3rd person singular je), the initial cluster /js/ is regularly simplified to a mere /s/. This pronunciation is considered correct and neutral when the verb is unstressed and used as an auxiliary. When stressed or used lexically, only the full /js/ pronunciation is considered correct. In casual speech, however, a few other highly frequent words commonly undergo similar simplification, namely all present forms of jít ("to walk") beginning with /jd/ (that is jdu, jdeš, jde, jdeme, jdete, jdou), the noun jméno ("name") and the verb jmenovat (se) ("to name, to (be) call(ed)").
Several words in Russian omit written consonants when spoken. For example, "чувствовать" (chuvstvovat') is pronounced [ˈt͡ɕustvəvətʲ] and "солнце" (solntse) is pronounced [ˈsont͡sə].
Russian letter ъ has no phonetic value and functions as a separation sign. Before the spelling reform of 1918 this hard sign was written at the end of each word when following a non-palatal consonant.
In Hebrew language, almost all cases of silent letters are silent aleph – א. Many words that have a silent aleph in Hebrew, have an equivalent word in Arabic language, that is written with a mater lectionis alif –ا ; a letter that indicates the long vowel "aa". Examples:
The explanation for this phenomenon is that the Hebrew language had a sound change of all the mater lectionis aleph letters into silent ones (see Canaanite shift). Due to that sound change, in Hebrew language, there are only two kinds of aleph - the glottal stop (/ʔ/) and the silent one, while in Arabic language all three kinds still exist.
The silent Arabic alif is marked with a wasla sign above it (see picture), in order to differentiate it from the other kinds of alifs. An Arabic alif turns silent, if it fulfils three conditions: it must be in a beginning of a word, the word must not be the first one of the sentence, and the word must belong to one of the following groups:
Besides the alif of the Arabic word ال (ʔal, meaning "the"), its lām (the letter L) can also get silent. It gets silent if the noun that word is related to, starts with a "sun letter". A sun letter is a letter that indicates a consonant that is produced by stopping the air in the front part of the mouth (not including the consonant M). The Hebrew equivalent to the Arabic word ال (ʔal, meaning "the") had totally lost its L.
In Maltese għ can be silent e.g. għar - meaning cave - and pronounced "ahr", or a voiced HH if it is followed by the or if it is at the end of a word e.g. qlugħ (q-glottal stop: qluh).
Unconventional to Sanskrit and Proto-Indo-European root languages, some Indic languages have silent letters. Among Dravidian languages, Tamil and Malayalam have certain distinct styles of keeping few of their letters silent.
Tamil is a classical language phonetically characterized by allophones, approximants, nasals and glottalised sounds. Some words, however, have silent letters in them. The words அஃது (while that is), and அஃதன் (that) contain the Āytam or 'ஃ', which is not pronounced in Modern Tamil. It is explained in the Tolkāppiyam that āytam could have the glottalised the sounds it was combined with, though some may argue it sounded more like the Arabic 'خ' (/x/). That being said, modern words like ஆஃபிஸ் (Office) use 'ஃ' and 'ப' in sequence to represent the sound, as the āytam is nowadays also used to transcribe it and other foreign phonemes.
Another convention in Middle Tamil (Sen-Tamil) is the use of silent vowels to address a mark of respect when beginning proper nouns. The Ramayana was one such text where the word Ramayana in Tamil always began with 'இ', as in இராமாயணம் (/ɾɑːmɑːjʌɳʌm/), though it was not pronounced. The name கோபாலன் (/ɡoːbɑːlʌɳ/) was so written as உகோபாலன் prefixed with an 'உ'.
Malayalam is a Sanskritized language in which speakers always pronounce all letters. The only known exception for consonants in the language is നന്ദി (/n̪an̪i/, thank you), where 'ദ' (/d̪a/) is never pronounced.
Thai has a deep orthography like English and French. Unlike the two languages, however, the Thai script is an abugida rather than a true alphabet. Nonetheless, silent consonants, vowels, and even syllables are common in Thai. Thai has many loanwords from Sanskrit and Pali, and rather than spell aforementioned words according to Thai phonics, the script tends to maintain the etymological spellings. For example, the word ประโยชน์ would be spelled in romanization as prayochṅ, but it would be pronounced as prayot, where the extra letter for -n is completely silent. Also, the Thai word มนตร์ is written as mantra like it would be in Sanskrit, but it is only pronounced mon in Thai. Though the second syllable is pronounced in Sanskrit, it is completely absent when pronouncing the word in Thai.
Also, different letters can be used for the same sound (for example, [tʰ] can be spelled as ฐ,ฑ,ฒ,ถ,ท, or ธ) depending on which class the consonant is, which is important for knowing which tone the syllable will have, and whether or not it is a loanword from Sanskrit or Pali. However, some letters written before low class consonants become silent and turn the low class syllable into a high class one. For example, even though the high class letter ho hip ห is used to write the sound /h/, if the letter comes before a low class letter in a syllable, the letter will become ho nam, which will make the letter silent and it will turn the syllable into a high class syllable. For example, the word นา is a low class syllable because its initial consonant is a low class consonant. The syllable is pronounced nā: (with a long vowel and mid tone) and it means "field". However, the word หนา is a high class syllable, despite it containing a low class consonant in the onset. The syllable is pronounced nǎ: (with a long vowel and a rising tone) and it means "thick".
Like Thai, Lao also has a letter that becomes silent if it comes before a low class consonant. The letter is ho sung ຫ, which would represent the sound /h/ if it were not paired with another low class consonant. However, unlike Thai, the digraphs beginning with the aforementioned letter can sometimes be written as a ligature.
In the standard Zhuang language, written in the Latin script, the last letter of every syllable is typically silent due to it representing the tone of the syllable. The digraphs mb and nd also have silent letters, representing the phonemes ɓ and ɗ respectively.
In the Hangul Orthography of the Korean language, the letter ⟨ㅇ⟩ is slient when written in the syllable-initial position, and represents the sound /ŋ/ when written in the syllable-final position. For example, in the word 안녕 (Yale Romanization: annyeng) (meaning "hello"), composed of the letters "ㅇㅏㄴㄴㅕㅇ", the first ⟨ㅇ⟩ is silent, and the last ⟨ㅇ⟩ is pronounced as /ŋ/. The reason for this can be found in 15th-century Hangul orthography. In the 15th century, the letter ⟨ㅇ⟩ originally represented /∅~ɣ/ (a lenited form of ㄱ /k/), while the letter ⟨ㆁ⟩ unconditionally represented /ŋ/. But because in Middle Korean phonology, ⟨ㆁ⟩ was not allowed in syllable-initial position, and ⟨ㅇ⟩ was not allowed in syllable-final position, it formed a complementary distribution of the two letters. Because of this and due to the fact that the letters look very much alike, the two letters merged.
Korean's syllable structure is CGVC, and Korean's writing system, Hangul, reflects this structure. The only possible consonant cluster in a single syllable must contain a glide and they must occur in the onset. However, sometimes a cluster of two consonants are written after the vowel in a syllable. In such situations, if the next syllable begins with a vowel sound, then the second consonant becomes the first sound of the next syllable. However, if the next syllable begins with a consonant sound, then one of the consonants in the cluster will be silent (sometimes causing fortition in the following consonant). For example, the word 얇다 (meaning "thin") is written as (Yale: yalp.ta), but the word is pronounced as if it was written yal.tta because the second syllable begins with a consonant sound. However, the word 얇아서 (also meaning "thin") is written as (Yale: yalp.a.se) and it is pronounced as yal.pa.se because the second syllable begins with a vowel sound.
Interestingly, the native Mongolian script has much more orthographic depth than Mongolian Cyrillic. For example, the letter Gh or γ (ᠭ) is silent if it is between two of the same vowel letters. In that case, the silent consonant letter combines to two written vowel into one long vowel. For example, the Mongolian word Qaγan (ᠬᠠᠭᠠᠨ) should be pronounced Qaan (ᠬᠠᠠᠨ). In Mongolian Cyrillic, however, it is spelled хаан (haan), closer to the actual pronunciation of the word. Words in the Mongolian script can also have silent vowels as well. For Mongolian name of the city Hohhot, it is spelled Kökeqota (ᠬᠥᠬᠡᠬᠣᠲᠠ) in Mongolian script, but in Cyrillic, it is spelled Хөх хот (Höh hot), closer towards the actual pronunciation of the word.