The Ular language was homogenous over a relatively long time. However, it splitted into two dialects from about 4500-4000. On 4000BK, three big Ular dialects were developed, each of them hardly understandable to the others. However, the dialects didn't form clear borders, but large borderlands where the dialects faded into each other. From 4000-2000BK, the big Ular dialects developed into own languages, due to the loss of the old Ular writing system.
The dialects didn't differ in their lexic very much, but had big differences in the pronunciation of Early Ular phones. That enabled the further-use of the old Ular writing system, which served as communication medium in the Old Ular Empire. While speakers couldn't understand much of each other, the writing system allowed an exact assignment at least of the Consonants. Therefore, you can say that Ular in 4000BK was not split into three languages, but formed a large dialect continuum which was held together by the writing system.
This dialect oriented on the language of the capital Mũg Thăw. So, it didn't differ much from Early Ular. It only made one sound shift:
[ѵ] < [b]
Due to that, Middle Ular only had one voiced plosive which had astonished the research for a long time.
This dialect was influenced much by indigenous peoples, so it made a lot more soundshifts. Also, it assumed lots of indigenous vocabulary and was the first dialect which developed to an own language (about 3500BK).
[pʰ] < [pß] < [ß]
[tʰ] < [ts] < [s]
[kʰ] < [kx] < [x]
Initial [ŋ] < [n] syllable-initializing, [k] as auslaut
Initial [n] < [ɲ]
[ɹ] and [l] fell together as [ɺ]
[a] before nasals < [æ]
[a] after fricatives < [ɑ̃]
[a] before nasals and after fricatives stayed [a]
[o] before nasals < [ø]
[o] after fricatives < [õ]
[o] before nasals and after fricatives stayed [o]
[u] before nasals < [y]
[u] after fricatives < [ũ]
[u] before nasals and after fricatives stayed [u]
This one changed a lot too, but not as much as Southern Ular. It formed a dialect continuum with Middle Ular until the Peram people landed on the Ular shore about 3000BK, even if it was hard to talk to each other.
Loss of distinction aspirated/non-aspirated in favor of distinction voiced/voiceless
[p] < [b], [bʰ]
[t] < [d], [dʰ]
[k] < [g], [gʰ]
[pʰ] < [p], [pʰ]
[tʰ] < [t], [tʰ]
[kʰ] < [k], [kʰ]
Some approximants formed new phones, but built an allophony with Middle Ular
[j] < [ʎ]
[l] < [ɫ] (sometimes, the flap ʟ changed too)
[w] < [ʍ]
[ɹ] < [ʁ] or [ʀ]
The further you went away from Mũg Thăw, the more differed those phones.
4200-3800BK, the phone system got reduced
The tone 5 (increasing) got loss and formed sandhi, whereas tone 3 vanished definetly and got fixed for the single morphemes as 1, 2 or 4.
Tone combinations (1 = up, 2 = falling, 4 = down, 5 = increasing, 6 = treole)
1 - 5 < 1 - 1
2 - 5 < 2 - 4
4 - 5 < 4 - 1
6 - 5 < 6 - 6
The woman was making laundry yesterday, when her children threw it into the dirt.
Transcription in Early Ular:
Phăn jón ngô kûng phăw, thŭ rán ká ngŏ rhán lhõ khúrh ăm.
(laundry woman make yesterday, when in dirt child lots her it throw)
The numbers mark the tone.
Middle Ular: [pʰan2 jon1 ŋo5 kuŋ5 pʰaw2, tʰu2 ɾan1 ka1 ŋo2 ɹan1 lo6 kʰuɹ1 am2]
Southern Ular: [ßan2 jøn1 no5 kuŋ5 ßɑ̃w2, sũ2 ɾæŋ1 ka1 no2 ɺan1 lo6 xũɺ1 æm2]
Northern Ular: [pan2 ʎon1 ŋo1 guŋ1 paʍ2, tu2 ɾan1 ga1 ŋo2 ʀan1 ɫo6 kuʁ1 am2]