Editing Vulgar Latin (section)

=== Loss of oblique cases ===
The Vulgar Latin vowel shifts caused the merger of several case endings in the nominal and adjectival declensions.{{sfn|Herman|2000|p=52}} Some of the causes include: the loss of final ''m'', the merger of ''ă'' with ''ā'', and the merger of ''ŭ'' with ''ō'' (see tables).{{sfn|Herman|2000|p=52}} Thus, by the 5th century, the number of case contrasts had been drastically reduced.{{sfn|Herman|2000|p=52}}
{| class="wikitable" align="center" style="display: inline-table;"
|+Evolution of a 1st declension noun:<br />''caepa/cēpa'' ("onion") (feminine singular)
|-
!
! Classical <br />(c. 1st century)
! Vulgar{{sfn|Herman|2000|p=52}}<br />(c. 5th cent.)
! Modern<br />Romanian
|-align="center"
! nominative
| ''caepa, cēpa''
| rowspan="3" | ''*cépa''
| rowspan="3" | ''ceapă''
|- align="center"
! accusative
| ''caepam, cēpam''
|-align="center"
! ablative
| ''caepā, cēpā''
|-align="center"
! dative
| rowspan="2" | ''caepae, cēpae''
| rowspan="2" | ''*cépe''
| rowspan="2" | ''cepe''
|-align="center"
! genitive
|}

{| class="wikitable" align="center" style="display: inline-table;"
|+Evolution of a 2nd declension noun:<br />''mūrus'' ("wall") (masculine singular)
|-
!
! Classical <br />(c. 1st cent.)
! Vulgar{{sfn|Herman|2000|p=52}}<br />(c. 5th cent.)
! Old French <br />(c. 11th cent.)
|-align="center"
!nominative
| ''mūrus''
| ''*múros''
| ''murs''
|-align="center"
! accusative
| ''mūrum''
| ''*múru''
| rowspan="4" | ''mur''
|-align="center"
! ablative
| rowspan="2" | ''mūrō''
| rowspan="2" | ''*múro''
|-align="center"
! dative
|-align="center"
! genitive
| ''mūrī''
| ''*múri''
|}

There also seems to be a marked tendency to confuse different forms even when they had not become homophonous (like the generally more distinct plurals), which indicates that nominal declension was shaped not only by phonetic mergers, but also by structural factors.{{sfn|Herman|2000|p=52}} As a result of the untenability of the noun case system after these phonetic changes, Vulgar Latin shifted from a markedly [[synthetic language]] to a more [[analytic language|analytic one]].

<!--I don't have the whole explanation of the disapparition of every case-->
The '''[[genitive case]]''' died out around the 3rd century AD, according to [[Wilhelm Meyer-Lübke|Meyer-Lübke]]{{obsolete source|date=January 2024}}<!--We need to know what the view of modern-day researchers is, not the opinion of someone who died in the 1930s. The article itself shows that his views have been superseded in some respects.-->, and began to be replaced by "de"  + noun (which originally meant "about/concerning", weakened to "of") as early as the 2nd century BC.{{Citation needed|date=December 2016}} Exceptions of remaining genitive forms are some pronouns, certain fossilized expressions and some proper names. For example, French {{wikt-lang|fr|jeudi}} ("Thursday") < Old French ''juesdi'' < Vulgar Latin "{{wikt-lang|la|diēs Iovis|jovis diēs|i=no}}"; Spanish ''es'' {{wikt-lang|es|menester}} ("it is necessary") < "est {{wikt-lang|la|ministeri|i=no}}"; and Italian {{wikt-lang|it|terremoto}} ("earthquake") < "{{wikt-lang|la|terraemotus|terrae motu|i=no}}" as well as names like ''Paoli'', ''Pieri''.{{sfn|Grandgent|1907|p=43-44}}

The '''[[dative case]]''' lasted longer than the genitive, even though [[Plautus]], in the 2nd century BC, already shows some instances of substitution by the construction "ad" + accusative. For example, "ad carnuficem dabo".{{sfn|Grandgent|1907|p=44}}<ref>[[Captivi]], 1019.</ref>

The '''[[accusative case]]''' developed as a prepositional case, displacing many instances of the [[ablative case|ablative]].{{sfn|Grandgent|1907|p=46-47}} Towards the end of the imperial period, the accusative came to be used more and more as a general oblique case.{{sfn|Herman|2000|p=53}}

Despite increasing case mergers, nominative and accusative forms seem to have remained distinct for much longer, since they are rarely confused in inscriptions.{{sfn|Herman|2000|p=53}} Even though Gaulish texts from the 7th century rarely confuse both forms, it is believed that both cases began to merge in Africa by the end of the empire, and a bit later in parts of Italy and Iberia.{{sfn|Herman|2000|p=53}} Nowadays, [[Romanian language|Romanian]] maintains a two-case system, while [[Old French]] and [[Old Occitan]] had a two-case subject-oblique system.

This Old French system was based largely on whether or not the Latin case ending contained an "s" or not, with the "s" being retained but all vowels in the ending being lost (as with ''veisin'' below). But since this meant that it was easy to confuse the singular nominative with the plural oblique, and the plural nominative with the singular oblique, this case system ultimately collapsed as well, and Middle French adopted one case (usually the oblique) for all purposes. 

Today, Romanian is generally considered the only Romance language with a surviving case system. However, some dialects of [[Romansh language|Romansh]] retain a special predicative form of the masculine singular identical to the plural: ''il bien vin'' ("the good wine") vs. ''il vin ei buns'' ("the wine is good"). This "predicative case" (as it is sometimes called) is a remnant of the Latin nominative in ''-us''.
{| class="wikitable" align="center"
|+ Evolution of a masculine noun<br />in Old French: ''veisin'' ("neighbor").<br /> (definite article in parentheses).
|-
! colspan="2" | !! Classical Latin<br />(1st cent.) !! Old French<br />(11th cent.)
|-align="center"
! rowspan="5" | singular
! nominative
| "<u>vīcīnus</u>" || (li) <u>veisins</u>
|-align="center"
! accusative
| "<u>vīcīnum</u>" || rowspan="4" | (le) <u>veisin</u>
|-align="center"	
! genitive
| "vīcīnī"
|-align="center"	
! dative
| rowspan="2" | "vīcīnō"  	
|-align="center"	
! ablative
|-align="center"
! rowspan="5" | plural
! nominative
| "<u>vīcīnī</u>" || (li) <u>veisin</u>
|-align="center"
! accusative
| "<u>vīcīnōs</u>" || rowspan="4" | (les) <u>veisins</u>
|-align="center"
! genitive
| "vīcīnōrum"
|-align="center"
! dative
| rowspan="2" | "vīcīnīs"
|-align="center"
! ablative
|}