Sindarin is a complex language created by J.R.R. Tolkien for his novels. It is the language of the Elves of Middle-Earth.
There are several different Elvish languages, but only Quenya and Sindarin were developed enough by Tolkien for us to communicate in.
Quenya was spoken by the Elves who journeyed from Middle-Earth to Aman. For those who did not finish the journey, their language changed over time and became Sindarin. The Elves who returned to Middle-Earth, the Noldor, learned to speak Sindarin. During the First Age Quenya was banned in Middle-earth as a language of Kinslayers, and became a language of ancient lore, not daily usage.
A lot of people write fanfic inspired by Lord of the Rings, and want to use "elvish" in their stories. Unfortunately, an internet search for "elvish" will likely produce something not-so-affectionately known as "Grelvish". This is a language created by a group of computer game role-players (the Grey Company) who wanted their Elves to speak "elvish" but found it too hard to learn Tolkien's languages, so they took a bit of Quenya, a handful of Sindarin, and random nonsense of their own, and mixed it all together. Their phrasebook has spread around the internet like a virus.
I offer in its stead a Phrasebook of genuine Sindarin expressions, sentences, questions, titles, and vocabulary. Many of the phrases are actual translations of the Grey Company's phrases, while others have been added. It is my hope that this phrasebook will be of use to all fanfic writers and roleplayers who love Tolkien's creation.
Lots of people express an interest in learning this language. It is not an easy task! Tolkien did not publish the language's grammar; in fact, he constantly revised the grammar, leaving us with often conflicting versions.
The best resource for learning about Sindarin is examining the Corpus, analyzing the attested published samples of Sindarin.
You're not a linguist? Ah, well then, you need to read the analysis by Helge Fauskanger at Ardalambion
You found that complicated? Ah, well, yes. So did I. That's why I have written a kinder, gentler version of Helge Fauskanger's analysis. You can find these simple grammar lessons at the Lord of the Rings Fanatics Plaza. The first five lessons are available now.
Be warned: There are a lot of sites on the internet that claim to teach "elvish", but I have yet to see one that does not teach errors. Some are terrible (I plan to make a Black List of sites to avoid), some are out-of-date, some teach Grelvish (a mix of Quenya and Sindarin and garbage), and some simply contain mistakes. Use these sites if you must, but also examine the writings at Ardalambion for a second (better) opinion.
Here are some aids for those interested in learning Sindarin:
Reconstructed Sindarin Vocabulary
~ A .doc dictionary of vocabulary, including verbs ~
Tara's Top Ten Tips for Studying Sindarin
~ How to begin learning Sindarin ~
Reconstructed Sindarin Verbs ~ Sindarin to English
~ A .doc file listing verbs reconstructed from the Etymologies~
Also available in an English to Sindarin listing
The Sindarin Corpus
~ The must-print attested samples from Tolkien's Writings ~
Chart of Consonant Mutations
~ A must-print for every Sindarin student ~
Table of Vowel Changes in Plurals
~ A convenient guide to those pesky umlauts ~
Chart of ALT-Codes
~ For writing the accents in Sindarin with a PC ~
Sindarin Personal Pronouns
~ A Reconstruction (one of many!) ~