Klingon

The Klingon language is from Star Trek. The details of the language were first put forth in the book The Klingon Dictionary by Marc Okrand, a linguist who was hired by Paramount Pictures to develop the language for the feature films. While not a complete language, Klingon is spoken by some dedicated Star Trek fans and to be able to converse in Klingon may be seen as the mark of a true geek.


 * Klingon Boggle is mentioned in the Pilot.


 * In The Bad Fish Paradigm (S2E01), Sheldon grills Penny on her qualifications to date Leonard. One of his questions for her is, 'Do you speak Klingon?'


 * The Panty Piñata Polarization (S2E07) opens with a game of Klingon Boggle.


 * In The Creepy Candy Coating Corollary (S3E05), Penny says she told the friend with whom she had hooked up Howard that he spoke five languages, to which Howard replies "Six, if you count Klingon!". Leonard remarks that "Girls don't count Klingon," and Penny agrees.


 * Later in The Creepy Candy Coating Corollary (S3E05), Sheldon taunts Wil Wheaton during the Mystic Warlords of Ka'a tournament at the comic book store by snarling a proverb in the Klingon language

"bortaS bIr jablu'DI' reH QaQqu' nay'

(commonly considered to be a Klingon proverb, invented by Marie Joseph Eugène Sue, meaning "Revenge is a dish best served cold!" )

.             Wil Wheaton hears and understands it.
 * In The Vacation Solution (S5E16), Penny think that Bernadette has talked Howard out of having their wedding invitations in Klingon, but Bernadette tells her that the Klingon text is on the back.
 * In The Countdown Reflection (S5E24), in the wedding of Howard and Bernadette, Sheldon tries to give the wedding speech in Klingon, but is stopped by Bernadette.