["K" Oxford English Dictionary, 2nd edition (1989); Merriam-Webster's Third New International Dictionary of the English Language, Unabridged (1993); "kay," op. cit.]
is the eleventh letter of the English alphabet
and the ISO basic Latin alphabet. In English, the letter K usually represents the voiceless velar plosive.
The letter K comes from the Greek letter Κ (kappa), which was taken from the Semitic kaph, the symbol for an open hand.
[ "K". The Oxford English Dictionary, 2nd ed., 1977, online] This, in turn, was likely adapted by Semites who had lived in Egypt from the hieroglyph for "hand" representing D in the Egyptian word for hand, d-r-t. The Semites evidently assigned it the sound value instead, because their word for hand started with that sound.
In the earliest Latin inscriptions, the letters C, K and Q were all used to represent the sounds /k/ and /g/ (which were not differentiated in writing). Of these, Q was used to represent /k/ or /g/ before a rounded vowel, K before /a/, and C elsewhere. Later, the use of C and its variant G replaced most usages of K and Q. K survived only in a few fossilized forms such as Kalendae, "the calends".
After Ancient Greek words were taken into Latin, the Kappa was transliterated as a C. Loanwords from other alphabets with the sound /k/ were also transliterated with C. Hence, the Romance languages generally use C and have K only in later loanwords from other language groups. The Celtic languages also tended to use C instead of K, and this influence carried over into Old English.
Use in writing systems
Today, English is the only Germanic language to productively use "hard" (outside the digraph ) rather than (although Dutch language
uses it in loaned words of Latin origin, and the pronunciation of these words follows the same hard/soft distinction as in English). The letter is usually silent at the start of an English word when it comes before the letter , as in the words "knight," "knife," "knot," "know," and "knee". Like J, X, Q, and Z, K is not used very frequently in English. It is the Letter frequency
in the English language, with a frequency of about 0.8% in words.
The SI prefix for a thousand is kilo-
, officially abbreviated as k
—for instance, prefixed to "metre" or its abbreviation m
signifies a thousand metres. As such, people occasionally represent numbers in a non-standard notation by replacing the last three zeros of the general numeral with "K": for instance, 30K for 30,000.
In most languages where it is employed, this letter represents the sound (with or without aspiration) or some similar sound.
The International Phonetic Alphabet uses for the voiceless velar plosive.
Ancestors, descendants and siblings
𐤊 : Semitic letter Kaph, from which the following symbols originally derive
Κ κ/ϰ : Greek alphabet letter Kappa, from which K derives
К к : Cyrillic letter Ka, also derived from Kappa
K with : Ƙ ƙ Ꝁ ꝁ Ḱ ḱ Ǩ ǩ Ḳ ḳ Ķ ķ ᶄ Ⱪ ⱪ Macron below
The Uralic Phonetic Alphabet uses various forms of the letter K:
ₖ : Subscript small k was used in the Uralic Phonetic Alphabet prior to its formal standardization in 1902
Ʞ ʞ : Turned capital and small k were used in transcriptions of the Dakota language in publications of the American Board of Ethnology in the late 19th century.
Turned small k was also used for a velar click in the International Phonetic Alphabet but its use was withdrawn in 1970.
Ligatures and abbreviations
₭ : Lao kip
Ꝃ ꝃ, Ꝅ ꝅ, Ꞣ ꞣ : Various forms of K were used for medieval scribal abbreviations
"K" replacing "C" in satiric misspelling.
K is the unit symbol for the kelvin, used to mesure thermodynamic temperature.
K is the chemical symbol for the Chemical element potassium ( K is an abbreviation of kalium, the Latin name for potassium).
Unit prefix k, meaning 1000 times.
K is the name of the principal character in Franz Kafka's novel The Trial.
In chess notation, the letter K represents the King (WK for White King, BK for Black King).
In baseball scoring, the letter K is used to represent a strikeout. A forwards oriented K represents a "strikeout swinging"; a backwards oriented K () represents a "strikeout looking".
As abbreviation for OK, often used in emails and short text messages.
K is used as a slang term for Ketamine among recreational drug users.
In the CMYK color model, K represents black ink.
In International Morse code it is used to mean "Voice procedure".
In fracture mechanics, K is used to represent the stress intensity factor.
In physics, k usually stands for Boltzmann's constant