QUENYA
Quenya is one of the many Elvish languages spoken by the immortal Elves, called Quendi in Quenya. The tongue actually called Quenya was in origin the speech of two clans of Elves living in Eldamar ("Elvenhome"), the Noldor and the Vanyar. The Teleri of Valinor spoke Telerin, a related language (sometimes described as a Quenya dialect) that developed on Tol Eressea. Quenya translates as simply "language", or in contrast to other tongues that the Elves met later in their long history "elf-language". In the Second Age some of the elite Númenoreans learned and spoke Quenya. In the Third Age, (the time of the setting of The Lord of the Rings) Quenya was no longer a living language for the Noldor of Middle-earth. Exilic Quenya was learned at an early age by all Elves of Noldorin origin, and it continued to be used in spoken and written form, but their mother-tongue was another Elven-tongue, Sindarin, originally spoken by the Sindar who were related to the Teleri but had never set foot in Valinor during the days of the Two Trees.
SINDARIN
Sindarin is one of the many languages spoken by the immortal Elves, called the Eledhrim or Edhellim in Sindarin. Called in English "Grey-elvish" or "Grey-elven", it was the language of the
Sindarin Elves of Beleriand. These were Elves of the Third Clan who remained behind in Beleriand after the Great Journey. Their language became estranged from that of their kin that sailed over sea. Sindarin derives from an earlier form of language called Common Telerin which itself had evolved from Common Eldarin, the tongue of the Eldar before their divisions, e.g. those Elves who decided to follow the Vala Oromë and undertook the Great March to Valinor. Even before that the Eldar Elves spoke the original speech of all Elves, or Primitive Quendian.
ADÛNAIC
One of the languages of Arda in Tolkien's Middle-earth legendarium, it was spoken by the Men of Númenor during the Second Age.
BLACK SPEECH
One of the languages of Arda in Tolkien's Middle-earth legendarium, it was spoken in the realm of Mordor. Tolkien describes the language as being created by Sauron as an artificial language to be the sole language of all the servants of Mordor, thereby 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.
TENGWAR
The Tengwar (Quenya for "letters"; singular tengwa "letter") are an artificial script created by J.R.R. Tolkien. In his fictional universe of Middle-earth, the tengwar were invented by the Elf Fëanor, and used first to write the Elven tongues: Quenya, Telerin, and also Valarin. Later a great number of languages of Middle-earth were written using the tengwar, including Sindarin. Tolkien used tengwar to write English: most of Tolkien's tengwar samples are actually in English.
CIRTH ('RUNES')
The Cirth are the letters of an artificial script which was invented by J.R.R. Tolkien for the constructed languages he devised and used in his works. The initial C in Cirth is pronounced as a K, never as an S.
