Working on creating an extended version of Khuzdul for The Lord of the Rings was a different challenge, both from translating into Quenya and Sindarin, and from simply inventing a new language out of the blue. In the first case, I had a large vocabulary and a general grammatical framework. In the second, I could do pretty much as I pleased. Khuzdul, however, though it had almost no indications of grammar and a very small vocabulary, nonetheless had a definite and distinctive sound and feel to it. It was going to be my task, before all else, to determine what that feel was and replicate it.
The first part of the job was relatively simple: to determine what the sounds of Khuzdul were, and the constraints upon the way those sounds could be organized. Simply by going through a list of all the Khuzdul words and names, I found the following sounds:
Vowels, short: i, e, a, o, u
Vowels, long: î, ê, â, û
Consonants, stops: b, d, g, t, th, k, kh, ʔ (glottal stop)
Consonants, fricatives: f, s, sh (i.e., /ʃ/), z, h
Nasals: m, n
Liquids and glides: l, r
Of course I knew that, given the small size of the Khuzdul corpus (the total number of words, names, and phrases in the language) this might not be all the sounds there were in the language, but each sound was repeated enough that it seemed to be pretty characteristic of the language. I decided that I wasn’t going to go outside this set of sounds without a very good reason.
The list of letters in the Angerthas, or runic alphabet, which is said to be used by the Dwarves that appears in Appendix E of The Return of the King appears, at first glance, to give a much larger variety of sounds. On closer consideration of its history and use, however, it turns out to be unreliable as a guide to Khuzdul sounds. The Dwarvish Angerthas is a fairly superficial remodelling of an earlier Elvish Angerthas, at first used for writing Sindarin (which explains the existence, for instance, of vowel sounds for ü and ö) and then supplemented by additional letters to write sounds found in other languages, which might include Khuzdul, but would also include Quenya, the Nandorin Elvish languages, and Mannish languages. And since the Dwarves always lived in contact with Men and Elves, they might have retained the same symbols for the same reason. The only sound that the description of the Angerthas specially pointed to as being part of Khuzdul was ʔ, “the clear or glottal beginning of a word with an initial vowel that appeared in Khuzdul.” By this I understood that when a word appears to begin with a vowel in Khuzdul — like uzbad, iglishmêk, or azanulbizar — it actually began with a ʔ, and this sound would or could be written in Khuzdul with the certh (rune) #35. (However, the word uzbad on Balin’s tomb actually doesn’t begin with this symbol.)
Appendix E’s pronunciation guide also pointed toward another distinctive characteristic of Khuzdul. Dwarvish is there said not to “possess the sounds represented… by th and ch (kh)” (meaning the sounds of English thick and German ach, represented in IPA by /θ/ and /x/) and that the written combinations of Roman letters th and kh actually represented aspirates — that is, IPA /tʰ/ and /kʰ/. The absence of /pʰ/ was notable, as was the presence of /f/ (as in felak-gundu, the Khuzdul name of the Elvish king Finrod Felagund). But my interpretation of these facts will be noted later.
The vowel system seemed fairly straightforward, with one exception: the extreme rarity of o (and the total absence of ô). The vowel o only appears in the name Gabilgathol, Khuzdul for Belegost/Mickleburg, and presumably also meaning “Great Fortress”. I decided that using a lot of o’s in my Khuzdul words would make it look very different from Tolkien’s, and I decided to avoid o where possible (though, as the language later developed, an ô later got in through the backdoor!). A system of just i, e, a, u looks somewhat “unbalanced,” when charted out: /i/ has /u/ as its back counterpart, but /e/ has no back counterpart at all. Of course, these symbols are, in principle, derived from equating the Khuzdul vowel-signs with their Elvish counterparts, and it’s quite possible that the Dwarvish values ascribed to these symbols were somewhat different. For instance, e might actually represent /æ/, a low front vowel, and a might represent /ɑ/, a low back vowel, in which case the symmetry would be complete. On the other hand, many natural languages do have asymmetrical vowel systems; so I decided not to worry too much about it.
The other question was about possible combinations of sounds. This was easy: there seemed to be no limitations. There was gl in aglâb, ʃm in iglishmêk, zb in uzbad, zd in Khuzdul, kʰs in rukhs, rb in Mazarbul, rbh in Sharbhund, rg in Nargûn, rk in bark and Tharkûn, nd in Bundushathûr, and various other combinations in what were more obviously compound words, like lg in Gabilgathol or lb in Azanulbizar. It seemed that wherever two consonants came together, they remained without change — and this, of course, made the task of construction considerably easier. It also gave the resulting words a very distinctive sound, less mellifluous, perhaps, than the Elvish languages, but more powerful.
But sounds were only the raw materials, the bricks and mortar of a building. In order to start building phrases and sentences, I needed words; and to get words, I needed an architectural plan, a way of bringing those sounds together in consistent shapes that would do two things at the same time: first, carry meaning; second, look and sound like Khuzdul. With this in mind, I proceeded to step two.