The Klingon language (, : , ) is the constructed language spoken by a fictional alien race called the Klingons in the Star Trek universe.

Described in the 1985 book The Klingon Dictionary by Marc Okrand, and deliberately designed to sound "alien", Klingon has a number of typologically uncommon features. The language's basic sound, along with a few words, was devised by actor James Doohan ("Scotty") and producer Jon Povill for Star Trek: The Motion Picture. The film marked the first time the language had been heard. In all previous appearances, Klingons spoke in English, even to each other. Klingon was subsequently developed by Okrand into a full-fledged language.

Klingon is sometimes referred to as Klingonese (most notably in the Star Trek: The Original Series episode "The Trouble with Tribbles", where it was actually pronounced by a Klingon character as "Klingonee" ), but among the Klingon-speaking community, this is often understood to refer to another Klingon language called Klingonaase that was introduced in John M. Ford's 1984 Star Trek novel The Final Reflection, and appears in other Star Trek novels by Ford.

The play A Klingon Christmas Carol is the first production that is primarily in Klingon (only the narrator speaks English). The opera is entirely in Klingon.

A small number of people are capable of conversing in Klingon. When Klingon was created, its vocabulary was heavily centered on Star Trek-Klingon concepts such as spacecraft or warfare, therefore it was hard for everyday use because of the lack of words for a casual conversation. With the release of the interactive "Learn Klingon" course of the Talk Now! series in September 2011, and the intense contact between Klingonists and Marc Okrand, the situation has changed; new words have been introduced, offering more everyday vocabulary.

History Creation The language is first mentioned in the original Star Trek series episode "The Trouble with Tribbles" (1967), but is not heard until Star Trek: The Motion Picture (1979). According to the actor who spoke the lines, Mark Lenard, James Doohan recorded the lines he had written on a tape, and Lenard transcribed the recorded lines in a way he found useful in learning them.

For Star Trek III: The Search for Spock (1984), director Leonard Nimoy and writer-producer Harve Bennett wanted the Klingons to speak a structured language instead of random gibberish, and so commissioned a full language, based on the phrases Doohan had originated, from Marc Okrand, who had earlier constructed four lines of Vulcan dialogue for Star Trek II: The Wrath of Khan.

Okrand enlarged the lexicon and developed a grammar based on Doohan's original dozen words. The language appeared intermittently in later films featuring the original cast; for example, in Star Trek V: The Final Frontier (1989) and in Star Trek VI: The Undiscovered Country (1991), where translation difficulties served as a plot device.

Okrand had studied some Native American and Southeast Asian languages, and phonological and grammatical features of these languages "worked their way into Klingon, but for the most part, not by design." Okrand himself has stated that a design principle of the Klingon language was dissimilarity to existing natural languages in general, and English in particular. He therefore avoided patterns that are typologically common and deliberately chose features that occur relatively infrequently in human languages. This includes above all the highly asymmetric consonant inventory and the basic word order.Okrent 2009, pp.270–271 Kwantlen journalist Robert Jago has pointed out similarities between Klingon and Halkomelem, a language spoken by the Indigenous people of the area where James Doohan grew up.

Internal history Within the fictional universe of Star Trek, Klingon is derived from the original language spoken by the messianic figure Kahless the Unforgettable, who united the Klingon home-world of under one empire more than 1500 years ago.

With the advent of the series Star Trek: The Next Generation (1987)—in which one of the main characters, Worf, was a Klingon—and successors, the language and various cultural aspects for the fictional species were expanded. In the episode "A Matter of Honor", several members of a Klingon ship's crew speak a language that is not translated for the benefit of the viewer (even Commander Riker, enjoying the benefits of a universal translator, is unable to understand) until one Klingon orders the others to "speak their [i.e., human] language".

A small number of non-Klingon characters were later depicted in Star Trek as having learned to speak Klingon, notably Jean-Luc Picard and Dax.

Canonicity An important concept to spoken and written Klingon is canonicity. Only words and grammatical forms introduced by Marc Okrand are considered canonical Klingon by the KLI and most Klingonists. However, as the growing number of speakers employ different strategies to express themselves, it is often unclear as to what level of neologism is permissible. New vocabulary has been collected in a list maintained by the KLI until 2005 and had since then been followed up by Klingon expert Lieven Litaer until the KLI's website was renewed in 2015.

Two "non-canon" dialects of Klingon are hinted at in the novelization of Star Trek III: The Search for Spock, as Saavik speaks in Klingon to the only Klingon officer aboard Cpt. Kruge's starship after his death, as the survivors of the Enterprise's self-destruction transport up from the crumbling Genesis Planet to the Klingon ship. The surviving officer, Maltz, states that he speaks the Rumaiy dialect, while Saavik is speaking to him in the Kumburan dialect of Klingon, per Maltz's spoken reply to her.

Language usage Speakers A small number of people are capable of conversing in Klingon. Arika Okrent guessed in her 2009 book In the Land of Invented Languages that there might be 20–30 fluent speakers. Its vocabulary, heavily centered on Star Trek–Klingon concepts such as spacecraft or warfare, can sometimes make it cumbersome for everyday use. For instance, while words for transporter ionizer unit () or bridge (of a ship) () have been known since close to the language's inception, the word for bridge in the sense of a crossing over water () was unknown until August 2012. Nonetheless, mundane conversations are possible among skilled speakers.

One Klingon speaker, d'Armond Speers of the Klingon Language Institute, raised his son Alec to speak Klingon as a native language, while the boy's mother communicated with him in English. Alec rarely responded to his father in Klingon, although when he did, his pronunciation was "excellent". After Alec's fifth birthday, Speers reported that his son eventually stopped responding to him when spoken to in Klingon as he clearly did not enjoy it, so Speers switched to English.

In 2007, a report surfaced that Multnomah County, Oregon, was hiring Klingon translators for its mental health program in case patients came into a psychiatric hospital speaking nothing but Klingon. Most circulations of the report seemingly implied that this was a problem that health officials faced before; however, the original report indicated that this was just a precaution for a hypothetical and that said translator would only be paid on an as needed basis. After the report was misinterpreted, the County issued another release noting that releasing the original report was a "mistake".

In May 2009, Simon & Schuster, in collaboration with Ultralingua Inc., a developer of electronic dictionary applications, announced the release of a suite of electronic Klingon language software for most computer platforms including a dictionary, a phrasebook, and an audio learning tool.

In September 2011, Eurotalk released the "Learn Klingon" course in its Talk Now! series. The language is displayed in both Latin and pIqaD fonts, making this the first language course written in pIqaD and approved by CBS and Marc Okrand. The course was translated by Jonathan Brown and Okrand and used the TrueType font.

In August 2016, a company in the United Kingdom, Bidvine, began offering Klingon lessons as one of their services.

There are Klingon language meetings and linguists or students are interested in researching this topic, even writing essays about the language or its users.

Klingon speakers are also referred to in non-Star Trek TV series, including Frasier, The Big Bang Theory, and Lucifer, and were heavily featured in the "My Big Fat Geek Wedding" episode of The Simpsons. In the 2017 film Please Stand By, in which a young autistic woman played by Dakota Fanning leaves her group home in San Francisco to deliver a Star Trek screenplay she wrote to Paramount Pictures, a Los Angeles police officer played by Patton Oswalt coaxes her out of hiding by speaking with her in Klingon.

Translated works Hobbyists around the world have studied the Klingon language. At least nine Klingon translations of works of world literature have been published, among which are: (Hamlet), (The Epic of Gilgamesh), (Much Ado About Nothing), (Tao Te Ching), (The Art of War), (The Rime of the Ancient Mariner), (The Wonderful Wizard of Oz), (The Little Prince), (Alice's Adventures in Wonderland), and (The Time Machine).

The Shakespearean choices were inspired by a remark from High Chancellor Gorkon in Star Trek VI: The Undiscovered Country, who said, "You have not experienced Shakespeare until you have read him in the original Klingon." In the bonus material on the DVD, screenwriter Nicholas Meyer and actor William Shatner both explain that this was an allusion to the German myth that Shakespeare was in fact German.

The Bible has been translated partially from English into Klingon. The Klingon Bible Translation Project, coordinated by Melanie Roney, translates the books of the Bible, both the Old and New Testaments, into Klingon. It is promoted by the Klingon Language Institute, whose goals do not include missionary work, but this project was considered worthy of KLI's efforts for purely secular reasons. The linguist and Lojbanist Nick Nicholas, who was responsible for translating Hamlet, has also translated the Gospel of Mark into Klingon.

In Strange New Worlds, S4E3, Human Best Friend, Number One (Rebecca Romijn) sings Bonnie Tyler's Total Eclipse of the Heart in Klingon.

Real world usage In July 2015, the Welsh Government issued a written statement in the Klingon language. Following a formal questioning of the Economy Minister Edwina Hart regarding the funding of research into UFO sightings around Cardiff Airport by Member of the Senedd Darren Millar, a press officer in the Minister's office issued the reply:

which was translated as: "The minister will reply in due course. However this is a non-devolved matter."

Use in other media

In the Quentin Tarantino film Kill Bill Volume 1 (2003), the opening of the film cites 'Revenge is a dish best served cold' as an 'old Klingon proverb'.

In 2010, a Chicago Theatre company presented a version of Charles Dickens' A Christmas Carol in Klingon language and a Klingon setting. On September 25, 2010, the Washington Shakespeare Company performed selections from Hamlet and Much Ado About Nothing in the Klingon language in Arlington County, Virginia. The performance was proposed by Okrand in his capacity as chairman of the group's board. This performance was reprised on February 27, 2011 featuring Stephen Fry as the Klingon Osric and was filmed by the BBC as part of a 5-part documentary on language entitled Fry's Planet Word.

The Java edition of Minecraft has a Klingon language setting.

The 2003–2010 version of the puzzle globe logo of Wikipedia, representing its multilingualism, contained a Klingon character. When updated in 2010, the Klingon character was removed from the logo, and substituted with one from the Ge'ez script.