X is the twenty-fourth letter in the modern Latin alphabet. Its name in English is spelled ex (pronounced /ɛks/),1 plural exes (pronounced /ɛksəz/).
History
The consonant cluster /ks/ was, in Ancient Greek, written as either Chi Χ (Western Greek) or Xi Ξ (Eastern Greek). In the end, Chi was standardized as /kʰ/ (/x/ in Modern Greek), while Xi was standardized for /ks/. But the Etruscans had taken over Χ from older Western Greek; therefore, it stood for /ks/ in Etruscan and Latin.
It is unknown whether the letters Chi and Xi are Greek inventions, or whether they are ultimately of Semitic origin. Chi was placed toward the end of the Greek alphabet, after the Semitic letters, along with Phi, Psi, and Omega, suggesting that it was an innovation; further, there is no letter corresponding specifically to the sound /ks/ in Semitic. There was a Phoenician letter 
ḥeth with a probable sound /ħ/, somewhat similar to /kʰ/, but this was adopted into Greek as first the consonant /h/, and later, the long vowel Eta (Η,η), and does not seem to have been the source of Greek Chi. The Phoenician letter 
Samekh (representing /s/) is usually considered the inspiration for Greek Xi, but as noted, Chi had a graphically distinct shape from Xi—although it may possibly have been another variant originally based on samekh. The original form of samekh may have been an Egyptian hieroglyph for the Djed column, but this too is uncertain, as no intervening Proto-Sinaitic form of this letter is attested.
| Egyptian hieroglyph "column" |
Phoenician S |
Greek Xi |
Greek Chi |
Etruscan X |
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Usage
In the International Phonetic Alphabet, [x] represents a voiceless velar fricative.
In some languages, as a result of assorted phonetic changes, handwriting adaptations or simply spelling convention, X has other pronunciations:
- Basque: as a spelling for [ʃ].
- Dutch: The island of Texel is pronounced as Tessel. This is because ss was written with a ligature closely resembling the x.
- English: X is a double consonant or, rather, a sign for the compound consonants [ks]; or sometimes when followed by an accented syllable beginning with a vowel, or when followed by silent h and an accented vowel [gz] (e.g. exhaust, exam); usually [z] at the beginnings of words (e.g. xylophone), and in some compounds keeps the [z] sound, as in (e.g. meta-xylene). It also makes the sound [kʃ] in words ending in -xion (typically used only in British-based spellings of the language; American spellings tend to use -ction). It can also represent the sounds [gʒ] or [kʃ], for example, in the words luxury and sexual, respectively. When the letter X begins a word in the English language such as xynene and a z sound is created the X is said to be silent. Final x is always [ks] (e.g. ax/axe) except in loan words such as faux (see French, below).
- French: at the ends of words, silent (or [z] in liaison if the next word starts with a vowel). This usage arose as a handwriting alteration of final -us. Two exceptions are pronounced [s]: six and dix.
- In Italian, X is always pronounced [[Help:IPA|ks], as in the words uxorio, extra, xilofono. It is also used, mainly amongst younger generations as a short form for "per" meaning "for", for example, x sempre (forever).
- In Norwegian, X is generally pronounced [ks], but since the nineteenth century there has been a tendency to spell it out as ks whenever possible; it may still be retained in names of people, though it is fairly rare, and occurs mostly in foreign words and SMS language.
- Spanish: In Old Spanish, X was pronounced [ʃ], as it is still currently in other Iberian languages. Later, the sound evolved to a hard [x] sound. In modern Spanish, the hard [x] sound is spelled with a j, or with a g before e and i, though x is still retained for some names (notably México, which alternates with Méjico). Now, X represents the sound [s] (word-initially), or the consonat clusters [ks] and [gs] (e.g. oxígeno, examen). Even rarer; like in Old Spanish, the x can be pronounced as [ʃ] in modern day in some proper nouns such as Raxel (a variant of Rachel) and Xelajú. In American and seseo Spanish, the xc in excelente is pronounced as [ks] but in Spain, this combination is pronounced [ksθ].
- Galician: In Galician (a language related to Portuguese and spoken in Northwestern Spain), x is pronounced as [ʃ] in most cases. In cultisms, such as 'taxativo' (taxative), the x is pronounced as [ks]. However, Galician speakers tend to pronounce it as s, especially when it appears in implosive position, such as in 'externo' (extern).
- In Portuguese, x can have four sounds: the most common is [ʃ], as in 'xícara' (cup). The other sounds are: [ks] as in 'fênix/fénix' (phoenix) and s, as in 'próximo' (close/next). The most rare is [z], as in 'exagerado' (exaggerate).
- In Albanian, x represents [dz], while the digraph xh represents [dʒ].
- Polish doesn't use X. In loanwords, X is either replaced by ks like in 'ekstra' (extra), or gz like in 'egzotyczny' (exotic).
- In the German and Italian languages, X is used mainly in foreign loan words.
- In Maltese x is pronounced [ʃ]
- In Vietnamese x is pronounced [s]
Additionally, in languages for which the Latin alphabet has been adapted only recently, x has been used for various sounds, in some cases inspired by European usage, but in others, for consonants uncommon in Europe. For these no Latin letter stands out as an obvious choice, and since most of the various European pronunciations of x can be written by other means, the letter becomes available for more unusual sounds.
No words in the Basic English vocabulary begin with X, but it occurs in words beginning with other letters. It is often found in a word with an E before it. X is the third most rarely used letter in the English language.
Codes for computing
Alternative representations of X
In Unicode the capital X is codepoint U+0058 and the lower case x is U+0078.
The ASCII code for capital X is 88 and for lowercase x is 120; or in binary 01011000 and 01111000, correspondingly.
The EBCDIC code for capital X is 231 and for lowercase x is 167.
The numeric character references in HTML and XML are "X" and "x" for upper and lower case respectively.
See also
References
- ^ "X" Oxford English Dictionary, 2nd edition (1989); Merriam-Webster's Third New International Dictionary of the English Language, Unabridged (1993); "ex," op. cit.
ḥeth with a probable sound /ħ/, somewhat similar to /kʰ/, but this was adopted into Greek as first the consonant /h/, and later, the long vowel Eta (Η,η), and does not seem to have been the source of Greek Chi. The Phoenician letter 
Samekh (representing /s/) is usually considered the inspiration for Greek Xi, but as noted, Chi had a graphically distinct shape from Xi—although it may possibly have been another variant originally based on samekh. The original form of samekh may have been an Egyptian hieroglyph for the Djed column, but this too is uncertain, as no intervening Proto-Sinaitic form of this letter is attested.
