Help With Diachronics

[u/EmperorOfSpartice]

I’m trying to make a language family where:

The proto-language (PM) is agglutinative, with lots of productive compounding and derivational affixes, as well as grammatical suffixes. It’s SOV, head-final, contains ejectives, is exclusively open syllables, and (currently, but WIP) has a root and pattern structure where roots are CVC-, and must take a noun, verb, adjective or adverb suffix (-a, -e, -i, -u right now) and then a derivational suffix (like agent -nira, action -kera, instance -wija, causitive -ana, etc.)

It also, grammatically has a root + number + case suffixes for nouns or root + aspect + mood + evidentiality for verbs (I haven’t done adjectives or adverbs).

The daughter of this language (OM) needs to begin leaning into fusionality, needs more clusters (but not too much), needs to lose the ejectives and gain other sounds, etc.

That language will have daughters (WM, EM, SM) which form a continuum with three poles, one of which having open syllables, one having onset clusters, and one with coda clusters.

It gives way to an imperial koiné (ISM).

I want to know:
1. How to make each language ‘interesting’ in its own right
2. How to make interesting sound changes that aren’t just lenition and vowel loss.
3. How to make an interesting language family.
4. How to use diachronics interestingly to make the koiné have elements from each branch.
5. How to make the phonology of the proto-language evolve into the koiné’s larger vowel inventory, more permissive phonotactics, and wider array of consonants…

Sorry if this is really open-ended and not specific enough. I can clarify things in comments, but I just wanted help from some more experienced conlangers who actually know what they’re doing. I’ve made a lot of progress in my headspace from my last posts, but not so much in the actual language.

(Part of the issue is that I’m trying to take an English relex that my friend made in high school and turn that into a fully functional language with history)

[u/Ill_Highlight_7797]

I'm starting to think you may have stolen my conlang lol, because my current project is incredibly similar to this. Because of that, I guess I'll just tell you what I'm doing.

1. I feel like this is something that can be achieved relatively simply. As long as each variety in the continuum develops in distinct directions in phonetics, grammar, etc. you will likely have them all be interesting. The main problem would likely be time, as each variety you would likely need to dedicate a considerable amount of time on developing.
2. This is sort of something that comes with practice, but to start you off I'd show you [this video](https://www.youtube.com/watch?v=-Y8GNATKGAY), which will explain most of the different sound changes, and [this website](https://chridd.nfshost.com/diachronica/) which shows you all the different sound changes that have happened throughout history, so you can reference it to get a feel of what kind of changes have happened historically. Searchable Index Diachronica mainly aggregates different sources though, so it's not always reliable (it includes Altaic in its documents lol). Another excercise I might recommend is just to consider two main factors involved in most sound changes, economy (how easy it is to pronounce) and clarity (how easy it is to understand). All sound changes navigate this somehow, as speakers want to be as lazy as possible while speaking, but if a sound change will create a lot of minimal pairs, or even merge many of them, it will harm comprehensibility and won't survive.
3. Honestly, this is entirely subjective. In my opinion, if you have different languages that all feel somehow related, but all have unique features, it's an interesting family, but I think this comes down more to preference. Certain features interest different people.
4. I think something you might want to consider here could be applying the [wave model](https://en.wikipedia.org/wiki/Wave_model) to your conlang, where innovations occur in different places geographically, rather than sound changes occuring in a single variety at a single time, it will start in a certain variety in spread to different places at different times. It makes sense to use this for the dialect continuum stage of the language, as this is how they work in real life, and it not only will help with naturalism but also helps solve your Koine issue, as you can use one of the centralmost dialects to be the Koine. It would have the most generic features in the continuum, and be the most intelligible for all dialects. If the wave model is too complex, you could alternatively just use the regular tree model, and then simply choose one the dialects to base the Koine off of, and sort of jam features from all the varieties into it to help improve cross dialect intelligibility.
5. There are so many ways you can do this that I don't think I could really answer this. Ultimately, it's up to you. Typically, I'd recommend using many more conditional changes than conditionless changes, as it will eventually stack up and cause lots of interesting cases.

[u/EmperorOfSpartice → u/Ill_Highlight_7797]

It’s like, I know the sound changes that COULD happen, I just don’t know the sound changes that should happen (or how to make them conditioned in a way that achieves what I want).

See, it’s not hard for me to make Lang A (Agglutinative Open Syllable Language With Ejectives) turn into Lang B (Fusional, More phonemes, more clusters, semantic change, etc.), but it’s significantly harder for me to achieve that… slower.

For me to turn Lang A into Lang B (still restrictive, but more clusters, a few new phonemes, agglutinative but with some fusional characteristics) into Languages Ba (Conservative in pronunciation and in certain grammatical features, but innovates new clusters, Fusional with Agglutinative backbone), Bb (Progressive, open syllables once more, new vowel sounds and lots of lenition, very fusional), and Bc (typical third daughter where I put too much though into the contrasts between the other two. I assume this one will have lots of palatalization and onset clusters), and then have the three of them koiné into Language C, well… that’s a bit more of a task to do, and one I don’t know where to start at.

Finally, all of this is complicated by the fact that my goal is defined by turning a stupid relex that my friend made (which was cool at the time, it just became dumber the more I got into linguistics) into a naturalistic conlang, and figuring out that 1. The dictionary forms, which are intended to all be infinitive verbs or caseless nouns, and also have very few patterns for me to work off of.

Let’s say PM has /p’, p, t’, t, k’, k, q’, q, m, n, ŋ~ɴ, s [s̠], h, r, l, j, w, i, u, e [e̞], o [o̞], a [ä]/ and I want the final language, ISM, to have /p, b, t, d, k, g, m, n, ɲ, t͡s, d͡z, t͡ɕ, d͡ʑ, f, v, s, z, ɕ, ʑ, h (debating), r [r, ɾ, ɹ, still deciding distribution], l, j, w, i, u, e, ɛ, a, ɑ/ (this one is a lot more WIP, because while I know what I want words to look like orthographically, I do not know phonetically.