The Klingon language (in Klingon, tlhIngan Hol) is a constructed language created by Marc Okrand for Paramount Pictures and spoken by Klingons in the fictional Star Trek universe. He designed the language with Object Verb Subject word order to give an alien feel to the language. Klingon is sometimes referred to as Klingonese, but among the Klingon-speaking community this is often understood to refer to another Klingon language, that described in John M. Ford's Star Trek novels as Klingonaase.
The Klingon language has the ISO 639 code tlh.
A description of the Klingon language can be found in Dr. Marc Okrand's book The Klingon Dictionary (Published by Pocket Books, Simon & Schuster, 1985, second edition with new addendum 1992, ISBN 067174559X). Other notable works include The Klingon Way (with Klingon sayings and proverbs), Klingon for the Galactic Traveler and the two audio productions Conversational Klingon and Power Klingon.
Three books have also been published in the tongue: ghIlghameS (Gilgamesh), Hamlet (Hamlet), and paghmo' tIn mIS (Much Ado About Nothing). These last two choices were inspired by a remark by a Klingon ambassador in Star Trek VI that Shakespeare is best read in the original Klingon.
Some Trekkers take the time to learn it and at some Star Trek conventions you can hear enthusiasts use it amongst themselves. They often greet each other with the Klingon word "nuqneH" (literally: "What do you want?"), which is said to be the closest thing to a greeting that exists in the language.
There was an attempt by Dr. d'Armond Speers to raise a child bilingually in English and Klingon; it was decided that Dr. Speers would speak in Klingon and that his wife would speak in English. A few years into its life, the child began rejecting Klingon and gravitating towards English. Klingon had lacked many words for things that were important in a baby's life, such as "diaper" (nappy) and "pacifier" (dummy). At the time, it even lacked words for many objects common around the house, such as "table".
In May 2003, the Multnomah County, Oregon Department of Human Services named Klingon on a list of 55 languages for which it might conceivably need interpreters; this story was circulated out-of-context as an urban legend claiming that the department was looking to hire a Klingon interpreter. County Chair Diane Linn called the listing the "result of an overzealous attempt to ensure that our safety net systems can respond to all customers and clients."  (http://www.snopes.com/humor/iftrue/klingon.asp)
Paramount owns a copyright to the official dictionary and other canonical descriptions of the language. Some people dispute the validity of Paramount's claim of copyright on the language itself in light of the Feist v. Rural decision, but no challenge has actually been brought to court.
Google is avaliable in Klingon.
This is a tentative list of the SAMPA and IPA transcription of the Klingon phonemes as listed in Okrand's book. <Angle brackets> represent orthography whereas /slashes/ represent phonemes in SAMPA and [square brackets] phonetic transcription in IPA. (See also  (http://www.klingonska.org/dict/tables.html).)
Klingon syllable structure is extremely strict: a syllable must start with a consonant (including the glottal stop) and a vowel, and may end with zero (fairly uncommon except in prefixes), a consonant or one of three biconsonantal codas: /-w' -y' -rgh/. Thus ta record, tar poison and targh targ (a type of animal) are all legal syllable forms, but *tarD and *ar are not.
Klingon is an agglutinative language, using mainly affixes in order to alter the function of words. Some nouns have inherently plural forms (jengva' plate vs ngop plates, for instance).
Klingon nouns take suffixes to indicate grammatical number, gender, two levels of deixis, possession and syntactic function. In all, 29 noun suffixes from five classes may be employed: jupoypu'na'wI'vaD for my beloved true friends.
Verbs in Klingon are even more complex, taking suffixes from nine classes. Verbs are marked for aspect, certainty, predisposition and volition, dynamic, causative, mode, negation, and honorific, and the Klingon verb has two moods: indicative and imperative.
Word order in Klingon is OVS, and in some cases the word order is the exact reverse of word order in English:
vaj mojaq.mey.vam DI.vuS.nIS.be' 'e' vI.Har thus-ADV suffix.PL.DEM 1pl-3pl.limit.need.not that 1sg-3sg.believe I believe that we do not need to limit these suffixes in this way
Cursing is considered to be a fine art among Klingons. That a person swears well is considered something of a compliment in Klingon culture. Some of the more common curse words include,
Some of the words are general invectives, others are personal epithets. Adding the term jay intensifies the words.
The official Klingon writing system is the Latin alphabet as used above, but on the television series, the Klingons use their own alien writing system. In The Klingon Dictionary this alphabet is named as 'pIqaD', but no information is given about it. When Klingon symbols are used in Star Trek productions they are merely decorative graphic elements, designed to emulate real writing and create an appropriate atmosphere.
The Astra Image Corporation designed the symbols currently used to "write" Klingon for Star Trek: The Motion Picture, although these symbols are often attributed to Michael Okuda. They based the letters on the Klingon battlecruiser hull markings (three letters) first created by Matt Jeffries, and on Tibetan and Devanagari writing because these scripts had sharp letter forms - a testament to the Klingons' love for knives and blades.
The font was extended to represent the entire english alphabet by Skybox (with many of the klingon letters representing more than one English letter and also the inclusion of an upturned and downturned triangle as punctuation) for writing klingon on numerous Paramount endorsed Skybox trading cards. Known cards include s7, s8 and s9 from Star Trek TNG's series 2 trading cards, season 5 card 509 (checklist B), cards s19 and s20 (which contain belittling comments aimed at a certain video loans company) and the season seven card selection s37, s38 and s39. These cards exist as the only canon translation of Klingon writing, though this is not well known. Due to its nature, the "Skybox" Alphabet is ill suited to writing Klingon, in that ambiguity in the alphabet is apparent, so different words are spelt the same way - these are homographs. The heartiest commendations and the gravest insults could be written identically, though it should be noted that context would go a long way to disambiguating homographs.
ya SoH - You are a tactical officer va SoH - You are a !%$@
Nevertheless, in September 1997 Michael Everson made a proposal for encoding this in Unicode. The Unicode Technical Committee rejected the Klingon proposal in May 2001 on the grounds that research showed almost no use of the script for communication, and the vast majority of the people who did use Klingon employed the Latin alphabet by preference.
A second script - again based more closely on the D7 battlecruiser hull markings - known as the Klinzhai or Mandel script, was included in The U.S.S. Enterprise Officer's Manual (1980), loosely upon the conceptual art of Matt Jeffries", TOS set designer. It maps to various letters and digraphs of English, but the phonemes have no discernable relation to Marc Okrand's Klingon Language.
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