Sauron created the Black Speech, as an artificial language, to be the sole language of all the servants of Mordor, replacing the many different varieties of Orkish and other languages used by his servants. Tolkien describes the language as existing in two forms, the ancient "pure" forms used by Sauron himself, the Nazgûl, and the Olog-hai, and the more "debased" form used by the soldiery of the Barad-dûr at the end of the Third Age. The only example given of "pure" Black Speech is the inscription upon the One Ring:
- Ash nazg durbatulûk, ash nazg gimbatul,
- ash nazg thrakatulûk, agh burzum-ishi krimpatul.
When translated into English, these words form the lines:
- One Ring to rule them all, One Ring to find them,
- One Ring to bring them all and in the darkness bind them.
These are the first two lines from the end of a verse about the Rings of Power.
Many Orkish dialects had adopted words from it. The Black Speech was at least in part based on Valarin.
In real life, J.R.R. Tolkien created this language with the intention of making it harsh and ugly, although people who speak the European languages that he emulated may disagree with his methods. The Black Speech is unfortunately one of the more incomplete languages in Tolkien's novels, because the forces of good refuse to utter it, as it attracts the attention of the Eye of Sauron. Unlike Elvish, there are no poems or songs written in it (apart from the Ring's inscription), and because Tolkien designed it to be unpleasant, he did not enjoy writing it. The result is a random collection of words that are hard to actually use in day-to-day conversation. We learn from the text in the ring and its translation that the Black Speech is a strongly agglutinating language.
For The Lord of the Rings: The Motion Picture Trilogy, the linguist David Salo used what little is known of the Black Speech to create enough of a language for use in the movies. This is usually referred to by Tolkienists as neo-Black Speech.