C (letter)
For other uses, see the C disambiguation page.
C is the third letter of the English alphabet, as it is in the Latin alphabet, where it originally appeared. In English its name is pronounced like see and sea, and is occasionally spelt out as cee.
C is also the Roman numeral representing the number 100.
History
C comes from the same letter as G. The Semites named it gimel, their word for a throwing stick. The sign is possibly adapted from an Egyptian hieroglyph for a boomerang. Some scholars claim that the Semitic gimel (ג) pictured a camel, but most assume it was probably gaml (a throwing stick or boomerang).
In the Etruscan language, plosive consonants had no contrastive voicing, so the Greek Γ (gamma) was adopted into the Etruscan alphabet to represent the /k/ phoneme. Already in the Western Greek alphabet, gamma first took a 
form in Early Etruscan, then 
in Classical Etruscan. Early Latin used C for both /k/ and /g/, but during the 3rd century BC, a modified character was introduced for /g/, and C itself retained for /k/. Hence, in the classical period and after, G was treated as the phonetic representative of "gamma", and C as the equivalent of "kappa", in the transliteration of Greek words into Roman spelling, as in "KA∆MOΣ, KYPOΣ, ΦΩKIΣ," in Roman letters "CADMVS, CYRVS, PHOCIS". It is also possible but uncertain that C represented only /g/ at a very early time, while K might have been used for /k/.
(As it happens, the Cyrillic letter es, an unvoiced labiodental sibilant, s in sun, has the same appearance as c, though it derives from one form of the Greek letter sigma, known as the "lunate sigma" from its resemblance to a crescent moon.)
Later use
When the Roman alphabet was introduced into Britain, C represented only /k/ and this value of the letter has been retained in loanwords to all the insular Celtic languages: in Welsh, Irish, Gaelic, C, c, is still only /k/. The Old English or "Anglo-Saxon" writing was learned from the Celts, apparently of Ireland; hence its c also originally represented /k/: the words kin, break, broken, thick, seek, were in Old English written cyn, brecan, brocen, Þicc, séoc. But during the course of the Old English period, /k/ before front vowels (/e/ and /i/) was palatalized, having, by the 10th century, advanced nearly or quite to the sound of /tʃ/, though still written c, as in cir(i)ce, wrecc(e)a. On the continent, meanwhile, a similar phonetic change had also been going on, for example, in Italian.
Original Latin /k/ before front vowels had palatalized in Italy to the sound of /tʃ/, and in France to that of /ts/. Yet for these new sounds the old character c was still retained before e and i, and the letter thus represented two distinct values. Moreover the Latin phoneme /kʷ/ (represented by QV, or qu) de-labialized to /k/, meaning that the various Romance languages had /k/ before front vowels. In addition, Northern French used the Greek letter k, so that the sound /k/ could be represented by either k or c, the latter of which could represent either /k/ or /ts/. These French inconsistencies as to c and k were, after the Norman Conquest, applied to the writing of English, which caused a considerable re-spelling of the Old English words. Thus while Old English candel, clif, corn, crop, cú, remained unchanged, Cent, cæ´
(cé´), cyng, brece, séoce, were now (without any change of sound) spelt Kent, keȝ, kyng, breke, seoke; even cniht was subsequently spelt kniht, knight, and Þic, Þicc, became thik, thikk, thick. The Old English cw- was also at length (very unnecessarily) displaced by the French qw, qu so that the Old English cwén, cwic, became Middle English qwen, quen, qwik, quik, now queen, quick. The sound /tʃ/ to which Old English palatalized c had advanced also occurred in French, chiefly (in Central French) from Latin c before a. In French it was represented by ch, as in champ, cher, Latin camp-um, caōr-um, and this spelling was now introduced into English: the Hatton Gospels, written about 1160, have in Matt. i-iii, child, chyld, riche, mychel, for the cild, rice, mycel, of the Old English version whence they were copied. In these cases, the Old English c gave place to k, qu, ch; but, on the other hand, c in its new value of /ts/ came in largely in French words like processiun, emperice, grace, and was also substituted for ts in a few Old English words, such as miltse, bletsien, in early Middle English milce, blecien. By the end of the 13th century both in France and England, this sound /ts/ de-affricated to /s/; and from that date c before front vowels has been, phonetically, a duplicate or subsidiary letter to s; used either for etymological reasons, as in lance, cent, or (in defiance of etymology) to avoid the ambiguity due to the "etymological" use of s for /z/, as in ace, mice, once, pence, defence.
Thus, to show the etymology, English spelling has advise, devise, instead of advize, devize, which while advice, device, dice, ice, mice, twice, etc., do not reflect etymology; example has extended this to hence, pence, defence, etc., where there is no etymological necessity for c. Former generations also wrote sence for sense.
Today
Hence, today the Romance languages and English have a common feature inherited from Vulgar Latin, where c takes on either a "hard" or "soft" value depending on the following vowel. In English and French, c takes the "hard" value /k/ finally and before a, o, and u, and the "soft" value /s/ before æ, e, i, œ or y. However, as one would expect with English spelling, there are a couple of exceptions: "soccer" and "Celt" are words that have a 'k' sound in the "wrong" place.
Romance languages obey similar rules, but the soft value is different in several languages, such as [s] in general, but a voiceless dental fricative /θ/ in Castilian Spanish and /ʧ/ in Italian, Romanian and Friulian. French, Occitan, Portuguese, Catalan, Aragonese and Francoprovençal have ç, "c cedilla", to make the c soft (sounding [s]) before a, o, and u. Friulian uses ç sounding [tʃ] before a, o and u.
Other languages use c with different values, such as /k/ regardless of position in Irish and Welsh; /θ/ in Fijian; /ʤ/ in Turkish, Tatar, and Azeri; /ʧ/ in Indonesian, Malay, and a number of African languages such as Hausa, Fula, and Manding; /ʦ/ in all Slavic languages that use the Latin alphabet, as well as Albanian, Esperanto, Hungarian, Ido, Interlingua, Latvian, and Lithuanian; and /tsʰ/ in Romanized Chinese. It is also used as a transliteration of the Cyrillic "Ц" in the Latinic forms of Serbian and Macedonian.
There are several common digraphs with c, the most common being ch, which in some languages such as German is far more common than c alone. In English, ch most commonly takes the value /ʧ/, but can take the value /k/ or /ʃ/; some dialects of English also have /x/ in words like loch where other speakers pronounce the final sound as /k/. CH takes various values in other languages, such as /ç/, /k/, or /x/ in German, /ʃ/ in French, /k/ in Interlingua and Italian, /ʈʂʰ/ in Mandarin Chinese, and so forth. CK, with the value /k/, is often used after short vowels in Germanic languages such as English, German and Swedish (but some other Germanic languages use kk instead, such as Dutch and Norwegian). The digraph cz is found in Polish and cs in Hungarian, both representing /ʧ/. In Old English, Italian, and a few languages related to Italian, sc represents /ʃ/ (however in Italian and related languages this only happens before e or i, otherwise it represents /sk/).
As a phonetic symbol, lowercase c is the International Phonetic Alphabet (IPA) and X-SAMPA symbol for the voiceless palatal plosive, and capital C is the X-SAMPA symbol for the voiceless palatal fricative.
Use in English
Though very common in English, c has (as in French, Portuguese, Catalan and many varieties of Spanish) no sound of its own. It is either in the back of the throat, exactly like k (kíng) and q (quêen) or it is a hiss, like the most common sound of s (sô), often, to distinguish from the buzzing z sound of s, ss as in híss. (The accents show stress and pronunciation: see English phonemes.)
c is actually more common than k - and much more than q - for the throaty sound. It occurs before back vowels a, o and u: cát, còme, còunt, cûre, côast, and liquid consonants l and r: clíck, crúst, clàss. In crícket, thícket, rácket, wícker, bícker, lócker, dócker, crácker, brácken, bráckish, lácking, the k is needed to show the throaty sound of the second c: without the k, the c would sound like an 's' because of the following e or i. Also, -ck is more common at the end of words as in déck and clóck. But after í, c is quite common finally: plástic, pánic, eléctric, frenétic, mûsic. Compare síc thus with síck ill. Also: mâniác, lîlac, ålmanác, blóc. By contrast, words do not end -ec or -uc.
The hissing s sound occurs before front vowels i, e and y: cïrcle, céntre, cŷcle, cínema, nîce, Lâcy, Trâcy, pâcy. For the hissing sound to remain before a back vowel, a cedilla is used in curaçào, soûpçon, façàde and Provençàl (*Provón-sàl).
The famous rule 'i before e except after c' applies only to the ê sound (and not to èi as in vèin): cêiling, decêit, recêive, recêipt (-êet).—And then, not only after c, as it happens: sêize, wêir, wêird, Nêil, Kêith and Shêila. Compare vèil, vèin, fèint pretend (= fâint swoon), dèign condescend (= Dâne Denmark), rèign queen (= râin wet), and also théir they (= thére here).
Quite often, especially at the beginning of a word, sc is used for the hissing sound before front vowels: scêne, scéptic, scîence, scént, scíssors, scîon, scintílla, scímitar, scythe, sciática (*sŷática).
In the suffix -ésce: acquiésce, effervésce, and pronounced z in créscent (*crézzənt).
An exceptional c is found in encephalîtis, pronounced k before e (enkéf-); otherwise c is always a hiss before e, i and y.
indîct, Tûcson and Connécticut all have a silent c.
ch most typically sounds like t plus sh – not like sh alone. French, German and Portuguese do not have this sound, although the Germans write it in foreign words as ‘tsch’. Spanish does have it, whence mácho (*mátcho: it is sometimes mispronounced ‘macko’, as if Italian). ch is common in English, which has taken French words like chàrm ('charme' in French) and modified the sound of the French ch, which has the English sh sound: chéck, choôse, chânge, Ríchard and also côach, bêach, chêek, chéss, chêer, cheŵ, escheŵ (which has a rare, separately sounded, s before it). Inside a word, there is often a superfluous t before ch: ítch, dítch, cátch, mátch, bùtcher - but never after r: tŏrch, lürch, àrch, except in names: Pàrtch person = pàrch tongue. And Tchaîkovsky has the T initially.
Uniquely, this sound is spelt Cz, however, in Czéch Republic, -oslovakia (= chéck determine = BrE chéque cash).
In some words more recently taken from French, ch sounds exactly like sh' in shê: machìne, nìche, pastìche, BrE moustàche, AmE moústáche, párachute, créche, Chicàgo and nónchalant, in which AmE French-style silences the t: *nonshalàn.
In other words, mostly from Greek, ch is k: chord, chémist, psŷchê, dichótomy, schême, àrchive, synécdochê, schoôner.
In two Celtic words ch can sound like the Arabic kh: lóch, Dócherty - but many people simply make the k sound here. And in the variant spelling Dóherty, the h sounds like itself alone - or kh or k.
In yacht, ch is silent: *yót.
ci before a vowel can have the sh sound: atrôcious (*atrôshəss), précious (*préshəss), magícian (*məjishən), Confûcius (*Kənfyoôshəss) - but never the zh sound, which is instead si: confûsion (*cənfyûzhən).
Double c has the k sound before back vowels (but for this, ck is far more common medially and finally): accŏrd, tobácco, accommodâtion, áccolâde, sóccer.
And the x sound before i and e: áccent, accépt, áccident, fláccid, áccess, succêed, succéss, váccine.
c begins consonant clusters: accépt (x sound, while accŏrd has no cluster, only the k sound), acknówledge, táckle, clûe, ácmê, acquîre, cróss, áct.
In names beginning Mc- and Mac- before another c, k or g, the c is silent, while the sometimes invisible a is in most cases pronounced with the schwa sound. It is as if the c itself were being pronounced schwa: McGóugh (*MəGóff), McCúrry, McCŏrmack, McKénzie = Mackénzie.
Either Mác or Mc can be stressed in a smaller number of names: MácIlvoy, McEnroe. In the latter the stressed syllable is an invisible a.
The c is always hard, even when not followed by a capital or k: McIntosh = MácIntosh = Máckintosh.
When capitalising, the c prefers to remain small: McINTOSH.
nc has the ng sound of the n in úncle and accidentally in páncake.
Final c is rather rare, except in the suffix -ic: plástic, jurássic, elástic, chrónic (k-) mánic; and Éric, chìc (sh-), Cádillac, Póntiac, Potômac and in abbreviations: tálc, mác. But *téc is téch.
To keep the c hard and prevent it becoming a hiss, a k is added to -ic before -ing and -ed: frólicking, pánicking, políticking, tráfficked.
But ck is much more common in monosyllables: síck, thíck, píck, wíck, críck, báck, déck, sóck, lúck, and as in jácket, crícket, píckle, níckel, pécker, lúcky.
After two vowel letters, k alone is always used: toòk, spoôk, sêek, roòk, wêek, lêak liquid = lêek vegetable, wêek, spêak, breâk, shrìêk.
Computer character encoding
In Unicode the capital C is codepoint U+0043 and the lowercase c is U+0063.
The ASCII code for capital C is 67 and for lowercase c is 99; or in binary 01000011 and 01100011, respectively.
The EBCDIC code for capital C is 195 for lowercase c is 131.
The numeric character references in HTML and XML are "C" and "c" for upper and lower case respectively.