Constructing an entire alien language is the most challenging task in all of speculative fiction, and there are two examples that tower above the rest: J.R.R. Tolkien's Elvish and Marc Okrand's Klingon. We'll show you how to outdo even them.
When it comes to world-building, there's no finer way to capture an alien culture than to give it a language that seems utterly strange to human ears. It's obviously a challenging task, and one that requires a decent working knowledge of linguistics. So while we have to leave the nitty-gritty of language construction to a textbook, what we can do is examine the very different overarching approaches used in constructing the two most iconic alien languages - Elvish and Klingon - and then explain how you could create a language that combines the best of both. So let's look at each one a time...
What J.R.R. Tolkien did with Elvish:
Tolkien, who considered himself a linguist and philologist first and an author second, once explained the true purpose of The Hobbit and The Lord of the Rings:
"Nobody believes me when I say that my long book is an attempt to create a world in which a form of language agreeable to my personal aesthetic might seem real. But it is true."
Tolkien's legendarium included dozens of languages that are variously mentioned, alluded to, translated to English, and in a few cases actually presented in their original form. Every race in The Lord of the Rings has its own language, although most remain largely unknown: the common speech of humans and Hobbits, known as Westron, is simply rendered as English in the books, the language of the Dwarves is a closely guarded secret that we only see glimpses of in character's names and the mines of Khazad-Dum, the brutish tongue Orcish is still too difficult for most Orcs to be able to speak it, and the true language of the tree-like Ents is so ancient and subtle that it lies beyond our comprehension.
But even with so many languages left unknown, there still is left a language family of staggering complexity. This is the Elvish languages, the very first things Tolkien created long before he came up with narratives to support them. There are about eight to ten such languages in the books, but two were given special attention: the ancient, ceremonial "Elven-Latin" language Quenya, and the commonly spoken Elven "lingua franca" Sindarin. As Tolkien said above, these were both attempts to create languages that reflected his own tastes in language, and so Quenya was based on Finnish while Sindarin was based on Welsh.
However, it was not enough for Tolkien to simply create two languages that happened to sound like Finnish and Welsh. Instead, he had to build up a logical history of sound and structural changes from a common proto-Elvish source that could conceivably produce both languages. As such, Tolkien approached language construction from the perspective of a historical linguist, one whose primary interest was charting the development of related languages over time.
His son Christopher, who has spent much of his own life compiling and analyzing his father's work, once explained just how painstaking a process this was:
"He did not, after all, 'invent' new words and names arbitrarily: in principle, he devised from within the historical structure, proceeding from the 'bases' or primitive stems, adding suffix or prefix or forming compounds, deciding (or, as he would have said, 'finding out') when the word came into the language, following it through the regular changes in form that it would thus have undergone, and observing the possibilities of formal or semantic influence from other words in the course of its history. Such a word would then exist for him, and he would know it."
Even more simply, Christopher Tolkien wrote in the introduction to "The Etymologies", a list of the basic Elvish building blocks Tolkien used to construct his languages, that "he was more interested in the processes of change than he was in displaying the structure and use of the languages at any given time." This is absolutely crucial, because it points to the basic shortcoming of Tolkien's work: his languages are by design really, really unfinished.
They were a constant work in progress, and Tolkien changed his mind over seemingly minor points several times in the course of his work. The list of definitive words and meanings that Tolkien left behind is relatively small, and though we know a little about how the Elvish languages sounded at many different points in their history, we don't really know a lot about the languages at any one specific time. Unsurprisingly, we have the best idea of how Quenya and Sindarin were spoken around the time The Lord of the Rings takes place, but even that is a very incomplete picture.
For our purposes, there's another problem: Tolkien's languages were not truly alien. In his cosmology, all the various races of Middle Earth shared a common, albeit remote, ancestry, and so their languages did share certain universal features. (It's a little more complicated than that, but satisfactorily explaining any part of Tolkien's world takes about a week, so I'll simplify.) That's why Sindarin and Quenya could indeed be based on Welsh and Finnish, and indeed why Tolkien could amuse himself by suggesting certain proto-Germanic words of uncertain origin actually came from Elvish. (If you're a linguist, that sort of thing is absolutely hysterical.)
In other words, Tolkien's work was a staggering achievement of historical linguistics and language construction, but it didn't leave us with complete languages, much less alien ones. Now let's take a look at our other iconic language...
What Marc Okrand did with Klingon:
Whereas Tolkien's work was simply a labor of love that could happily last a lifetime, Marc Okrand was working under a rather more firm deadline when he devised Klingon. He first became involved with the Star Trek franchise when he helped out with the "dubbing" of Vulcan dialogue in The Wrath of Khan, and the filmmaker were so impressed with his work that they asked him to create an entire Klingon language for The Search for Spock.
Okrand, a former linguistics professor who was working (and still works) on closed captioning at the National Captioning Institute, leaped at the opportunity to invent Klingon. He wanted to remain true to what little Klingon had been heard before, which was comprised entirely of a few character names from the original TV show and some lines of dialogue from the opening of Star Trek: The Motion Picture. Using this meager data set as an entry point to Klingon, Okrand first figured out what sounds had already been used in Klingon, and then built up the phonetics of the language from there.
As he explained in a lecture video that we've embedded below, he intentionally violated as many rules of human language as he could. Human languages are unbelievably varied, and there's really no such thing as a true universal, a rule that holds true in 100% of cases. However, there are a lot of features of language sounds, meanings, and grammar that are very common in almost all human languages, and it would be highly unusual if none of these appeared in a human language. Of course, since Klingon isn't a human language, he tried to violate as many of these as possible.
He explains a few such instances where he made intentionally odd sound choices: "So, for example, in Klingon, there's the sound "v" and usually in a language if there's a "v" sound there's also an "f" sound. Not in Klingon. Why? Because usually that's the way it works in human languages and Klingon is not a human language. In Klingon, there's a "t" sound and there's also a "d" in Klingon, but the "d" doesn't match the "t" – you make it putting your tongue in a different place. That's unusual from a human language point of view, therefore that's a good thing to do in Klingon. There's a number of things like that which is violating the rules or tendencies of human phonetics."
He took a similar approach with the grammar of Klingon:
"The basic order of the words, I had to figure out. The three basic elements of a sentence are the subject, the verb, and the object. The subject is who's doing the action, the verb is what is the action, and the object is who's receiving the action assuming that's appropriate to the sentence. Part of the grammar of English is knowing where in the sentence does the subject and the object fall because otherwise you don't know who is doing what to whom. If you look around at all the different languages, there's all kinds of different orders these things can fall in – it doesn't have to be the way English is. In fact, in some languages it can be any old thing because you mark who's doing it with little suffixes or something like that. But ignoring that for the time being…
Mathematically, there's six possible combinations: subject-verb-object, subject-object-verb, verb-object-subject, verb-subject-object, object-subject-verb, object-subject-verb, and object-verb-subject. And all of these things are represented in languages in the world somewhere or other, although some are much more common than others. So if you take this weird notion that the most common is the most human and the least common is the least human, then for Klingon I should pick the least common. Not because for any other reason than it's found in the fewest human languages. And the least common are the ones with the object first, and [object-verb-subject] is the one I chose for Klingon. I chose it - It's found in a few languages in the world, not very many, as the basic word order."
The end result of this work was not limited to what Christopher Lloyd and companied barked in Star Trek III. The Klingon Dictionary first appeared in 1985 and was updated in 1992. It's sold a half million copies, spawned an iPhone app, and helped give rise to the Klingon Language Institute, dedicated to preserving the Klingon language. (So it's sort of like the French Academy, except, you know...with Klingon.) But Klingon, for all its comprehensiveness, is missing one rather gigantic aspect of any real language: it has no history. That's where you come in.
What You Can Do:
What we have here are two very different approaches to language creation. Tolkien's efforts are very much the work of a historical linguist, so paramount above all else is the construction of Elvish languages that show clear change and development through time. Etymologies are crucial to Tolkien's works, each word a work of art forming a rich tapestry that reaches back deep into the temporal dimension. This was his life's work, an ongoing project to which he devoted decades and likely wouldn't have completed if he had had centuries.
Marc Okrand, on the other hand, had a much more immediate task: to transform a handful of Klingon names and a few lines of dialogue into a fully-formed language in time for Star Trek III to start filming. He approached this task as a structural linguist, concentrating on the phonetics and grammar to build up a fully-formed Klingon tongue. The language he devised is far more comprehensive than either of the Elvish languages, and there's a lot more you can say in Klingon than the other two. (There would be absolutely no way to write an Elvish Hamlet while confining oneself to just Tolkien's work, for instance, but Klingon Hamlet is ready to ship.)
What Klingon lacks, however, is history. While we can use Tolkien's etymologies to quite accurately reconstruct what Elvish sounded like millennia before The Lord of the Rings, Klingon remains time-locked in the 23rd and 24th centuries. You only need to pick up, well, Hamlet to realize how much English has changed in the last few centuries, so there's every reason to assume the way Klingons would speak their language in 2010 is very different from how they talk in Star Trek.
But there isn't really any way to guess at historical language change based on Klingon as it is now. The etymologies just aren't there to make reconstructions possible, and any attempt to invent patterned language change would quickly reveal just how ad hoc the construction of Klingon was. None of this is meant to diminish Okrand's singular achievement but merely to point out this wasn't what he was trying to do.
That's where you, budding legend of speculative fiction, come into the picture. Tolkien create historically rich languages that were essentially human. Okrand create truly alien languages that had no history. The next great alien language will be the one that combines the best of these two approaches, devising a language with both alien structure and alien history. Klingon already provides the perfect tutorial on how to make a language sound like it's from another planet, so I'll leave that aside. But how do you make languages encode an unearthly history?
That's the puzzle I'll leave you with, although I can offer a few possibilities to get you going. In fact, Marc Orkand's introduction to The Klingon Dictionary provides a great example of how Klingon reflects a truly alien culture:
"...there are no words for greetings, such as hello, how are you, good morning, and so on. It seems apparent that such words and phrases simply do not exist in Klingon. When two Klingons meet each other (except in cases where military protocol determines behavior), if anything of an introductory nature is said, it is an expression that can best be translated as What do you want? Unlike most speakers of English, who begin conversations with greetings, inquiries about the state of health of the conversants, and remarks about the weather, Klingons tend to begin conversations by simply stating the main points."
That's the sort of thing to think about, and then just add a historical dimension. Did Klingon once have such greeting words, but then the complete militarization of its culture removed them? Or did perhaps meanings decay and change over time? If they never existed at all, what does that say about the origins of Klingon civilization? Moreover, just as Marc Okrand created Klingon by looking at features of human languages and turning them on their head, think about ways to invert the usual patterns of human language change. I'll conclude by looking at the biggest one, and the closest thing humanity has to a true language universal, and how flipping it could create an entire alien race.
As a rule, languages only split apart, never merge together. French and Spanish came from Latin, but they couldn't recombine into a neo-Latin. But what if an alien culture was capable of bringing two languages together into a new, unified tongue? Would such an alien species have to be telepathic to negotiate the difficulties of merging meanings and structures together? The very exercise of creating a species that could conceivably merge two languages together would by necessity create an unusually rich and well-developed alien culture. These are the sorts of challenges awaiting the constructor of the next great alien language, but I'd say they would be well worth the effort.