Phonotactics

Phonotatics are, roughly speaking, which sound constructions a language allows and which sounds strange and difficult. It's how the minimal sounds interact together to make words.

Using English as example, this is the reason why an English word like *plunber or *enbryo doesn't exist - English forbids /nb/ - but *plumber and *embryo is OK because English allows /mb/.

Phonotactics change from language to language - what is an acceptable word in one language is not in another.

So, while English allows lots of consonants in the same syllable, Japanese allows only one or two - so, while "sprite" /sprait/ is an OK English word, Japanese speakers try to pronounce it like /supuraito/ (スプライト)

Languages with lax phonotactics (English, Russian) have lots of different syllables, and use lots of one-syllable words. This comes with a cost - they're hard to learn how to pronounce. Languages with restrict phonotactics (Japanese, Mandarin, Portuguese) are far easier to learn how to pronounce, but uses bigger words, lots of homophones (same-sounding words) or hard to distinguish sounds.

Langian's phonotactics are roughly based in Italian's and Spanish's, see below. й/j and ў/w will be called "consonants" in explanations to make them simpler.

SYLLABLE START/ONSET
(i.e., before the vowel) Zero, one or two consonants.

If only one consonant, can be any of them.

Two consonants are allowed only in these situations:


 * First one is an occlusive (п/p т/t к/k б/b д/d г/g) and second one is /r/ (p/r) (so пр/pr is OK, мр/mr is not OK); or


 * First one is any except ў/w й/j ч/z and second one is ў/w or й/j (so бй/bj is OK, but ўй/wj or чйа/zj are not OK).

SYLLABLE CENTER
(i.e. the central vowel) V - any of five vowel, but:
 * There is no ўу/wu or уў/uw - in these cases, change it to ўo/wo or oў/ow;


 * There is no йи/ji or ий/ij - in these cases, change it to йe/je or eй/ej.

SYLLABLE END/CODA
(i.e. after the vowel, but still in same syllable) Zero consonant, or any of these:

ф/f


 * с/s


 * х/h


 * й/j


 * ў/w


 * н/n

TL;DR: max syllable CCVC.