There are few grammatical features more captivating and enigmatic than the tri-consonantal or
trilateral root system.
In the Semitic languages, like Hebrew, Arabic, and Syriac, a root isn’t a concrete, pronounceable
form, it’s just a string of three consonants associated with a particular semantic domain.
To make a functional word, these three consonants are slotted into one of a number of vowel
templates, which, in conjunction with a handful of more typical prefixes and suffixes, form
the basis of verb conjugations, nominal plurals, and derivational strategies.
When you first come across it, it just seems so novel and so different from the way almost
any other language is structured that, naturally, there’s a temptation to include this kind
of system in a conlang.
And to do that, all you have to do is make all your roots in the form of three consonants,
then make up some vowel patterns and ascribe meanings to them.
Now, that’s totally fine if naturalism isn’t a priority to you, or if you’re going for
something more surface-level and don’t really care about the details, but if you’re aiming
for maximal naturalism, that’s not really how these things work.
The vast majority of languages have morphology that works in terms of concatenation, attaching
prefixes and suffixes to stems to modify their meanings.
But occasionally in natural languages, we find morphology that appears inside a stem.
The triconsonontal root system represents an extreme form of this non-concatenative morphology.
So, to make a naturalistic triconsonantal root system, we need to understand where this
nonconcatenative morphology comes from.
Let’s make a quick test language for illustrative purposes.
We’ll give it a pretty simple phonetic inventory, a CVC syllable structure, and stress that
always falls on the second-to-last syllable.
One of the most common forms of non-concatenative morphology is vowel alternation, in which
grammatical meanings are encoded by changes in the vowel of the stem.
And one of the easiest ways to make this happen is umlaut, sometimes called i-mutation, in
which a high front vowel can trigger assimilation of the preceding vowel.
In particular, the vowel [i] is pronounced with the tongue far forward and raised to
the palate, and in preparation for this maneuver, the vowel of the previous syllable might get
pronounced closer to where the [i] is pronounced so the tongue doesn’t have to move as far.
This has the effect of fronting and/or raising the vowel before the [i], with the exact change
in quality depending on the language’s phonology.
So perhaps in our test language, there’s a suffix of the form [i], which replaces the
final vowel of the stem.
Then we implement umlaut, which, for simplicity, we’ll say turns any preceding vowel into
another [i].
Then, if word-final vowels are lost, now we have a grammatical inflection that was once
indicated by a suffix, but is now signified by a change in vowel quality.
Although most common with [i], a final [e] may also cause fronting of a preceding vowel,
and, though a bit rarer, an [a] vowel might drag previous sounds down and further back.
So if we have a suffix with a prominent, long [a] vowel, it may turn the previous vowel
to an [a].
But word-internal changes can be a lot more substantial than just vowel alternation.
Sometimes extra consonants or even entire syllables can wind up embedded inside a stem.
These are called infixes, and they’re much, much rarer than prefixes and suffixes.
If we want to create some infixes, there’s really only one thing for it: metathesis,
a sound change wherein two sounds in a word trade places.
Metathesis isn’t particularly common and it’s often quite unpredictable,
but one motivation for it is, much like with umlaut, the anticipation of an upcoming sound.
In American English, some speakers pronounce the word “cavalry” as “calvary”, which
happens when the tongue is moved into position for the [l] before pronouncing the [v], and
then the [l] just bleeds over.
In our test language, we could use this same trick to get some infixes.
If we have some auxiliaries that get suffixed onto the lexical verb, then say that a sequence
consisting of any consonant followed by [l] or [r] will cause the sounds to switch places,
now we’ve managed to get these consonants inside our stems.
And while we’re at it, coda liquids also very frequently cause wacky effects on the
vowels that precede them.
Quite often, languages will make fewer vowel distinctions before a rhotic, or r-like sound, than elsewhere.
Not only that, but coda [r] can sometimes just disappear entirely, leaving a long vowel
in its wake, much like in my dialect of English.
We can do this in our test language, having any vowel occurring in a syllable with a coda
[r] becoming [a], and then the [r] is lost and the [a] undergoing compensatory lengthening.
Meanwhile coda [l] can be quite volatile.
Sometimes it turns into a [j] and sometimes it becomes [w], thereby turning the vowel
in the nucleus into a diphthong, which in turn, might get simplified to a monophthong
over time.
If our coda [l] turns into a [j], then all the resultant diphthongs may eventually become reduced
to a long [i].
Now, what started out as infixation born of metathesis has become another form of vowel
alternation.
Metathesis may also occur to make sounds easier to hear.
If we have a prefix “ka-“, and then we say that vowels are lost in unstressed syllables,
we might end up with some rather infelicitous clusters, like a word-initial /ks/.
In this environment, the /k/ is a little bit difficult to enunciate and to hear clearly.
One of the ways of fixing this is to say that all word-initial sequences of a stop followed
by a fricative are metathesized.
Now, in addition to making the form easier to pronounce, we’ve got ourselves an infix!
You may notice that the steps we’re taking to implement infixation rely on certain phonetic
conditions being met, unlike most prefixes and suffixes.
It’s partly for this reason that infixes are so rare in comparison to other kinds of morphology.
However, some languages, like Tagalog and many of the other Austronesian languages,
are replete with infixes to a seemingly inexplicable degree.
The secret to this abundance of non-concatenative morphology lies in these languages’ syllable
structure; namely, they all forbid consonant clusters.
So, when a consonant-final word becomes prefixed onto a consonant-initial word, an illegal
cluster is formed.
And it looks like the way these sequences were dealt with is by metathesizing the entire
prefix with the initial consonant, the result being a plethora of infixes.
Although after vowel loss in unstressed syllables, our test language seems pretty content with consonant
clusters, maybe it later decides to disallow word-initial and word-final clusters.
One way to deal with these is with epenthesis, the adding of a sound to prevent an otherwise
illegal sequence.
In our case, we’ll insert a short [u] to break up any illegal clusters.
Now, by this point, you may be wondering to yourself, “when are we actually going to make a triconsonantal
root system?”
Well, lets zoom out and have a look at what we’ve done so far.
If we take an example verb and conjugate it for the forms we’ve made, what
we end up with is a system of entirely non-concatenative morphology, and, In fact, from a synchronic
perspective, we could very well analyze this as if the root is S-P-T and that this root
fits into one of these pre-determined vowel templates to form grammatical meanings.
Voila, we’ve got ourselves a triconsonantal root system!
Now, this is just a fairly simple example and nowhere near as prolific as the systems
in the Semitic languages, but it should hopefully give you an idea of how systems like this
can come about.
However, if we conjugate some more verbs, we see that the patterns we’ve made don’t exactly work 100%.
This incongruence is partially to be expected.
All natural languages display some degree of irregularity, especially those with systems like this.
In Arabic, even something as simple as pluralization has dozens of different patterns, so it’s
no surprise that the system might be a little haphazard when it first evolves.
But the human mind has a very strong tendency to make order out of chaos, and in the case
of language, this manifests as analogy.
In linguistics, analogy is, in a way, the opposite of irregularity;
instead of creating exceptions to a rule, analogy spreads the rule to areas where it wasn’t previously applied.
A frequent result of this is the reanalysis and subsequent loss of old irregular forms
Once the triconsonantal root system has been firmly established, and speakers are accustomed
to these patterns, analogy can go a long way to standardize the system by ironing out some
of the inconsistencies.
One pretty obvious thing that will need to be taken care of is the fact that this system
only works with roots that have exactly three consonants.
If the triconsonantal root system is perceived as the “regular” pattern, then the speakers
may go out of their way to make sure words can fit into it.
One way this might be done is through appending words with extra morphology.
In English we have the verb trap, to which we can add the prefix ‘en-‘, to make a
word that means… pretty much exactly the same thing.
A similar process could be used to add an extra consonant to any two-consonant stems
to make them fit with the triconsonantal system.
And if this affix begins with a fricative, then the [k] infix will apply, and if this
strategy is used for all old two-syllable roots, then the infix will be quite common,
so much so that words that don’t use the infix may be considered irregular.
And over time, the speakers may get so used to the [k] infix signifying nominalization,
that they reanalyse the irregular forms as having a [k] infix as well, while the “correct”
prefixed forms fall out of use.
Likewise, a verb root with [r] as the final consonant won’t fit the pattern for the
future tense, but even so, it may be so ingrained in the mind of the speakers that a long [i]
between the second and third consonant encodes the Future, that they’ll apply the vowel
alternation to words in which it never previously occurred.
There will always be at least some irregularity, especially in more common words, but with
analogy, we can clear up a lot of the clutter of all these competing patterns and establish
our non-concatenative system as the dominant, “regular” marking scheme.
So in summary, to make a naturalistic triconsonantal root system, or indeed any non-concatenative
system, use the phonology of prefixes and suffixes to influence changes within the stem,
then minimize the prominence of the prefixes and suffixes as much as possible, so that
the grammatical information is conveyed by the stem change.
Then employ analogy to spread the “regular” paradigm to words whose phonology made them
resistant to the sound changes that produced the pattern.
For further reading on the evolution of the Semitic triconsonsantal systems, as well as
a bunch of other stuff, I highly recommend the book The Unfolding of Language by Guy
Deutscher, while for more on infixing, check out A Natural History of Infixation by Alan C. Yu
And if you’re looking to learn more about analogy, then, as luck would have it,
I’ve been asked to lend some assistance regarding this exact topic, so join me on
the Worldbuilding Notes Channel to see how Ewa and I can incorporate some analogy into her conlang.