This article presents the sound changes that happened from Latin to Romanian. The order in which the sound changes are listed here is not necessarily the order in which they actually happened in reality. Sound change or phonetic change is a historical process of language change consisting in the replacement of one speech sound or, more generally, one phonetic feature by another in a given phonological environment. ... Latin is an ancient Indo-European language originally spoken in the region around Rome called Latium. ...

Vulgar Latin period

Iotacization

In Vulgar Latin, short /e/ and /i/ followed by another vowel were changed to a semivowel /j/. Later, /j/ palatalized the preceding consonant, changing its quality. The results in modern Romanian are:

• Lat. puteum > *putju > Rom. puţ, but:
• Lat. rōgātiōnem > *rogatjone > *rogačone > Rom. rugăciune (prayer)
• Lat. hordeum > *ordju > *ordzu > Rom. orz (barley), but:
• Lat. deorsum > *djosu > *džosu > Rom. jos (down)
• Lat. socium > *sokju > Rom. soţ (companion, husband)
• Lat. cāseum > *kasju > Rom. caş (type of cheese)
• Lat. vīnea > *vinja > *viɲe > Rom. vie /vije/
• Lat. mulierem > *muljere > *muʎere > Rom. muiere /mujere/ (woman)

Notice that the dental plosives t and d were changed to postalveolar affricates before o and to alveolar affricates before other vowels. This alternation is still productive in modern Romanian, cf. credinţă (faith) - credincios (faithful), oglindă (mirror) - oglinjoară (little mirror).

In the case of the labials, the /j/ underwent metathesis and the labial consonant stayed unchanged:

• Lat. rubeum > *robju > Rom. roib

Vowels

The Latin vowels a, o and u remained unchanged (not in absolutely all words, see below):

• Lat. mare > Rom. mare (sea)
• Lat. pālum > *paru > Rom. par (pole)
• Lat. focum > *focu > Rom. foc (fire)
• Lat. pōmum > *pomu > Rom. pom (fruit-bearing tree)
• Lat. multum > *multu > Rom. mult (much)
• Lat. tū > Rom. tu (thou)

Latin short u seems to have been lowered to o when stressed and before m or b in some words:

• Lat. *autumna (from autumnus) > *tomna > Rom. toamnă (autumn)
• Lat. *rubeum > *robju > Rom. roib

Also, Latin long ō was changed to u in a few words:

• Lat. cohortem > *cōrtem > Rom. curte

Vowels e and i underwent the following changes:

• short, stressed e was lowered to *ɛ
• short, unstresesd e', long ē and short i merged into *e
• long ī remained i

Here are some examples:

• Lat. pellem > *pɛlle > Rom. piele /pjele/ (skin)
• Lat. signum > *semnu > Rom. semn (sign)
• Lat. vīnum > *vinu > Rom. vin (wine)

Also, it can be supposed that Latin ae was also changed to *ɛ when stressed, but there is no direct evidence for this. Some time later, *ɛ became the diphthong */je/.

Consonants

Individual consonants did not undergo major changes. The labialized velar plosives were changed to labials before a and to plain velars before other vowels; in question words beginning with qu-, this was never changed to p- (presumably through analogy):

• Lat. quattuor > *quattro > Rom. patru (four)
• Lat. equa > *ɛpa > *jepa > Rom. iapă (mare)
• Lat. lingua > *lemba > Rom. limbă (tongue)

• Lat. quid > *ke > Rom. ce (what)
• Lat. quandō > *kando > *kându > Rom. când (when)
• Lat. sanguis > *sange > Rom. sânge (blood)

Another important change is the labialization of velars before dentals, which includes the changes ct > pt, gn > mn and x > ps. Later, ps was simplified to s in most words.

• Lat. factum > *faptu > Rom. fapt (fact, deed)
• Lat. signum > *semnu > Rom. semn (sign)
• Lat. coxa > *copsa > Rom. coapsă (thigh), but:
• Lat. laxō > *lapso > *lasu > Rom. las (I let)

Final consonants

All final consonants were lost. As a consequence, there was a period in the history of Romanian in which all words ended with vowels.

Up to Proto-Romanian

Rhotacism of l

At some point, intervocalic l was changed to r. From the evolution of certain words, it is clear that this happened after the above-mentioned iotacization, but before the simplification of double consonants (as ll did not change to r) and also before the palatalization due to following i. Some examples:

• Lat. gelu > Rom. ger (frost)
• Lat. salīre > Rom. a sări (sărire) (to jump)

Palatalization

The dental consonants t, d and s were palatalized again by a following i or j (from the combination je < ɛ < stressed e):

• Lat. testa > *tɛsta > *tjesta > *ţesta > Rom. ţeastă (skull)
• Lat. decem > *dɛke > *djeke > *dzeče > Rom. zece (ten)
• Lat. servum > *sɛrbu > *sjerbu > Rom. şerb (serf)

• Lat.
• Lat. dīcō > *dziku > Rom. zic (I say)
• Lat.

Weakening of unstressed vowels

Unstressed a became ă (except when at the beginning of the word) and unstressed o became u. Then ă became e after palatal sounds. Unstressed o was kept in some words due to analogy.

• Lat. capra > Rom. capră (goat)
• Lat. vīnea > *vinja > *viɲă > *viɲe > Rom. vie /vije/ (vineyard)
• Lat. fōrmōsum > Rom. frumos (beautiful)

Backing of e

The vowel e was changed to ă when preceded by a labial consonant and followed by a back vowel in the next syllable (i.e. it stayed e when the following vowel was i or e):

• Lat. mēnsam > *mesa > *măsă > Rom. masă (table), but
• Lat. mēnsae > *mese > Rom. mese (tables)

• Lat. vēndō > *vendu > *văndu > *vându > Rom. vând (I sell), but
• Lat. vēndis > *vendi > *vendzi > *vindzi > Rom. vinzi (you sell)

Modern changes

These are changes that did not happen in all dialects of Romanian. Some belong to the standard language, while some do not.

Changing of voiced affricates into the corresponding fricatives

In southern dialects, and in the standard language, dz is lost as a phoneme, becoming z in all environments:

• dzic > zic (I say)
• lucredzi > lucrezi (you work)

The affricate dž became j only when hard (i.e. followed by a back vowel):

• gioc /dʒok/ > joc (game), but:
• deget /dedʒet/ (finger) did not change.

Insertion of a glide /j/ between â and soft n

This affects only a few words:

• pâne > pâine (bread)
• câne > câine (dog)

It also explains the plural mână - mâini (hand(s)). This is also specific to southern dialects and the standard language; in other regions one may hear câne etc.

Hardening of ş, ţ and dz

This is specific of northern dialects. It means that these consonants can only be followed by back vowels, so any front vowel is changed to a back one:

• şi > şî (and)
• ţine > ţânʲe (holds)
• dzic > dzâc (I say)