Language in the Celegian Empire
There is only one language in official usage in the Empire and that one has been in use for a very long time indeed. It is called Celegian and in linguistic terms it is an INCREDIBLY old language, having existed for over one thousand centuries in a form still recognizable. The main reason it has not drifted far from its linguistic roots in all that time is the constant effect of the Gods, especially Teb. He has influenced the culture and taught the classic forms of the language without change, preventing idiomatic drift to a large extent. In addition, the written form of the language is simple and fixed, with two types of written characters. The two types are letters and runes. Letters are those we are familiar with, each representing a set of sounds, which are used to spell out words phonetically. The alphabet is composed of 22 letters, all of which correspond to one of our letters. Celegians have no letter for Z, C, J, or Q. This alphabet is combined with a much larger and more complex set of characters known as runes.
Runes have evolved from the very early days of the Empire as a type of "shorthand." Each runic symbol conveys a complete, complex thought concept. There are runes which stand for bountiful times, war, worshipful reverence, safe haven, dangerous presences, joyous revelry, etc. Many Celegian words are composed of one or more runes combined with one or more letters. The best aspect of this system of writing is the fact that the meanings of the runes are fixed and do not change, so that in the very oldest records the meaning of the entire record can be deduced by the runes used in it.
No matter the effort spent on keeping the language constant, over the length of the Empire's history some linguistic drift has been inevitable. The runes allow the old records to remain legible, even though the spoken language has undoubtedly changed. The worst part is the fact that there are so many different runes, hardly anyone is fluent in all of them. Most people have a spoken vocabulary of a few thousand words and can read about half that. The total number of runes alone is over ten thousand, and the number of words is far higher than that. Words in which there are both runes and letters usually have the meaning of the rune, modified by the prefix or suffix.
Celegian runes are loosely derived from an even older and more complex language called Ancient Lelnian. Lelnian is a totally rune based language and few of the runes are exactly the same as those used in Celegian. Lelnian is still spoken by the elite nobility and is a sign of a comprehensive education. Spoken Lelnian is fluting and lovely to hear, and the runic form makes the written language very compact, with complicated concepts embodied in a few characters. No one today knows how many runes Lelnian has, but it is at least ten thousand and possibly many more. Lelnian is often used as a code of sorts by high government officials and the nobility when they wish to discuss things which it is suited for. Lelnian is not well suited for accountancy or bookkeeping, as it does not deal well with hard concepts. It is very well suited for poetry, psionics, and magic, as well as topics involving interrelationships between people. Lelnian has no term for money, but has twenty-three words for various forms of emotional love and thirty-seven words for states of hatred. In general Celegian is a better language overall, but Lelnian is exotic and specialized.
Even older that Ancient Lelnian is Latin, a language much beloved by scribes, scholars, ciphers, and other non-magical professionals of great intellect. Latin is a very precise language that uses only an alphabet, although that alphabet uses 37 letters to match nearly every possible phoneme, including glottal stops and fricatives. There is little to no spoken Latin, as that portion of the language has been lost. But written Latin is rigidly formed and remains legible in even the very oldest records. Latin is well suited to ciphers and philosophers and is often called the language of intellect. If you wish to learn the highest intricacies of Imperial thought, you must know how to read and write latin. Now, it is perfectly possible for Celegian Mages and Sages to learn other languages, such as Abyssal, Infernal, Celestial, and the like, because those languages originate from other Planes. Even more widespread in the more distant realms are other languages.
Celegia is very much a human dominated Empire, but every race is represented somewhere in the Realms and every language as well. If a scholar travels and studies hard enough, there are dozens of languages available to learn. But no matter where you go, you will always find people who are speaking Celegian, and the familiar runes will be everywhere you need to be.