[Coda]

Technically it's all made up, but Tolkien was a linguist and he put a ridiculous amount of effort into building the fictional languages used in his worlds. He developed the full grammar of each language, a substantial (but not comprehensive) vocabulary for each, and orthographies (writing systems) for not only each language but even for regional variations -- not rigidly consistent, but realistic in how it might have evolved across separated groups of people. He even included subtle derivations that would suggest that his fantasy languages might have been able to evolve from ancient real-world languages. A LOT of this stuff was found in Tolkien's notes instead of his published material.

Since then, fan groups have expanded on the vocabulary and extrapolated on the grammar, finding rules and patterns that are consistent with the examples spoken by the characters in the books in order to document things that Tolkien hadn't necessarily explicitly spelled out.