Milk from lactem

Lactem gave lapte, noctem gave noapte, factum gave fapt. All three went through the same change: the cluster ct became pt. Each word went through others as well, and none of them depends on what the word means. A sound change depends on the neighbouring sounds, and it happens wherever the same conditions are met.

Order matters. In caballum, simplify the double consonant before the l between vowels turns into r, and you end up with car. Apply the other rule first and leave the ll intact, and you get cal, the Romanian word for horse.

The twenty-four rules

Each rule applies to every matching position in the word at once. The example shows a word from the game where the rule does its work.

• -m, -s → –the ending dropsWord-final m and s stop being pronounced in late Latin.lupum → lup
• -u → –final -u dropsLost after a single consonant, kept after clusters such as -dr- (codru) and after a vowel (bou).lupum → lup
• -a → -ăfinal -a becomes -ăUnstressed final a reduces to the central vowel ă.casam → casă
• ct → ptct becomes ptThe consonant made at the back of the mouth is replaced by one made at the lips. The same lactem gave latte in Italian, leche in Spanish and lait in French.lactem → lapte
• gn → mngn becomes mnAgain a replacement by a consonant made at the lips, this time a nasal one.pugnum → pumn
• x → psx becomes psThe letter x stood for the sounds cs, and the c becomes p just as in the cluster ct.coxam → coapsă
• qu → pqu becomes pThe cluster, made with rounded lips, reduces to p: aqua, equa, quattuor.aquam → apă
• CC → Cdouble consonants simplifyLatin distinguished anus from annus by the length of the consonant. Romanian gave that distinction up.vallem → vale
• VlV → VrVintervocalic l becomes rOnly a single l. A double ll is not affected, which is why the order of these two rules matters.salem → sare
• VbV, VvV → VVb and v drop between vowelsThe consonant weakens between vowels until nothing of it is left.ovum → ou
• VV → Vtwo identical vowels mergeOnce a consonant drops, the two vowels left side by side merge into one.caballum → cal
• o → oastressed o becomes oaOnly when a, ă or e follows in the next syllable. Hence poartă but porți.portam → poartă
• e → iestressed e becomes ieThe stressed short vowel diphthongises: an i appears in front of it.pellem → piele
• e → iastressed e becomes iaThe same diphthongisation; with a or ă in the next syllable, the second element is a.petram → piatră
• a → â / _m, na becomes â before a nasalBefore a nasal consonant, a closes toward the central vowel â.campum → câmp
• e → i / _m, ne becomes i before a nasalThe vowel e closes to i: dentem gives dinte, bene gives bine.lentem → linte
• o → u / _m, no becomes u before a nasalThe same closing before a nasal: pontem gives punte.pontem → punte
• ĭ → eshort i becomes eLatin distinguished a long i from a short one. The difference was there in speech even though writing did not mark it, and short i became e. The result could then undergo further changes: lingua gave limbă.siccum → sec
• ae → eae becomes eThe classical diphthong reduces to a plain vowel in later spoken Latin.caelum → cer
• h → –h disappearsIt had not been pronounced for centuries by the time Romanian formed; spelling kept it out of habit.herbam → iarbă
• CVC → CCthe unstressed vowel fallsThe vowel of an unstressed syllable, before l, r or n, is lost outright: oculum becomes oclu.merulam → mierlă
• cl → chi, gl → ghicl and gl softenThe l becomes an i, and the consonant before it is palatalised.oculum → ochi
• li → ili before a vowel becomes iThe l disappears and the i stays on as part of the diphthong.filium → fiu
• ti → țti before a vowel becomes țThe t is palatalised before the i and yields the affricate ț.pretium → preț

All forty derivations

The Latin form is the accusative, because that is what the Romanian word descends from. The chain shows the shortest run of rules that leads from etymon to modern word.

• lupum → lupu → lupLat. lupum, “wolf”
• casam → casa → casăLat. casam, “hut”In Classical Latin, casa was the hut, not the stone dwelling; that was domus, which was lost from Romanian.
• focum → focu → focLat. focum, “hearth”The hearth stood in the middle of the house, and ignis, the Latin word for flame, disappeared from Romanian.
• lactem → lacte → lapteLat. lactem, “milk”
• factum → factu → faptu → faptLat. factum, “deed”
• coctum → coctu → coptu → coptLat. coctum, “cooked, baked”
• pugnum → pugnu → pumnu → pumnLat. pugnum, “fist”
• aquam → aqua → aquă → apăLat. aquam, “water”
• vallem → valle → valeLat. vallem, “valley”
• annum → annu → anu → anLat. annum, “year”
• salem → sale → sareLat. salem, “salt”
• gulam → gula → gulă → gurăLat. gulam, “gullet, appetite”In Romanian the name spread from gullet to mouth, and os, oris, the classical word for mouth, disappeared.
• ovum → ovu → ouLat. ovum, “egg”
• caballum → caballu → cabalu → caalu → calu → calLat. caballum, “pack horse, nag”Caballus was the poor working horse. The masculine equus left no inherited descendant in the Romance languages, though the feminine equa gave Romanian iapă, mare.
• portam → porta → portă → poartăLat. portam, “gate”
• florem → flore → floareLat. florem, “flower”
• solem → sole → sore → soareLat. solem, “sun”
• noctem → nocte → nopte → noapteLat. noctem, “night”
• coxam → coxa → coxă → copsă → coapsăLat. coxam, “hip”
• pellem → pelle → pele → pieleLat. pellem, “skin”
• ferrum → ferru → feru → fieru → fierLat. ferrum, “iron”
• petram → petra → petră → piatrăLat. petram, “rock”
• campum → campu → câmpu → câmpLat. campum, “field”
• lanam → lana → lană → lânăLat. lanam, “wool”
• lentem → lente → linteLat. lentem, “lentil”
• pontem → ponte → punteLat. pontem, “bridge”Pod came later from Slavic, and punte narrowed to the footbridge.
• montem → monte → munteLat. montem, “mountain”
• siccum → siccu → sicu → secu → secLat. siccum, “dry”
• nigrum → nigru → negruLat. nigrum, “black”
• lignum → lignu → limnu → lemnu → lemnLat. lignum, “wood”
• caelum → caelu → celu → ceru → cerLat. caelum, “sky”
• cognatum → cognatu → comnatu → cumnatu → cumnatLat. cognatum, “blood relative”Romanian narrowed the sense from blood relative to relative by marriage.
• herbam → herba → herbă → hiarbă → iarbăLat. herbam, “grass”
• filium → filiu → fiiu → fiuLat. filium, “son”
• pretium → pretiu → prețu → prețLat. pretium, “price”
• merulam → merula → merulă → mierulă → mierlăLat. merulam, “blackbird”
• trifolium → trifoliu → trifoiu → trifoiLat. trifolium, “clover”
• scandulam → scandula → scandulă → scandură → scândurăLat. scandulam, “shingle”
• directum → directu → direptu → dreptu → dreptLat. directum, “straight, direct”
• oculum → oculu → oclu → ochiu → ochiLat. oculum, “eye”

Back to the game

How this was checked

None of the forty derivations is written by hand. Every intermediate form on the page is what the rule named beside it produces, run through the same engine you use while playing. The step count given as the minimum is the shortest run found by a breadth-first search over the rules, up to eight of them.

The game applies its rules to written forms, while the historical changes affected pronunciation. Latin spelling marks neither stress nor vowel length, though both shape how a vowel develops: the rule “short i becomes e” applies here to any i, because spelling does not show which one was short. Likewise the game accepts any order that reaches the target, while the real chronology of the changes is fixed and settled in the handbooks. The chains here reconstruct the result for the reader without dating the stages.

Inherited words generally descend from the accusative rather than the dictionary nominative, which is why we start from lupum and not lupus. The exceptions are known: om continues the nominative homo, and for neuters the two forms coincided anyway.

To check whether the rules hold beyond the words chosen here, I gave them an independent list: the 660 Romanian words that Wiktionary records as inherited directly from Latin, whose etymon is given without intermediate links and in a form the engine can start from. For 152 of them the rules produce exactly the Romanian form, among them fugă, turmă, bine, coastă, lână, lingură, piedică and mire. The rest need changes these twenty-four rules do not cover, or start from a nominative too far from the form the word descends from — lac for lapte, nox for noapte.

Sources

• Wiktionary, English edition — the Latin etymons, inheritance chains and glosses. Content under the CC BY-SA 4.0 licence.
• Marius Sala, De la latină la română, Univers Enciclopedic, Bucharest, 1998 — the reference description of the sound changes used here.
• Alexandru Rosetti, Istoria limbii române de la origini până la începutul secolului al XVII-lea, Editura Științifică și Enciclopedică, Bucharest, 1986 — the detailed treatment of consonant clusters and of vowels before nasals.