Editing Latin declension (section)

=== {{anchor|d4}}{{anchor|Fourth declension}} Fourth declension (''u'' stems) ===
The fourth declension is a group of nouns consisting of mostly masculine words such as {{wikt-lang|la|flūctus|flūctus, flūctūs}} {{abbr|m.|masculine}} ('wave') and {{wikt-lang|la|portus|portus, portūs}} {{abbr|m.|masculine}} ('port') with a few feminine exceptions, including {{wikt-lang|la|manus|manus, manūs}} {{abbr|f.|feminine}} ('hand') and {{wikt-lang|la|domus|domus, domūs}} {{abbr|f.|feminine}} ('house'). The fourth declension also includes several neuter nouns including {{wikt-lang|la|genu|genū, genūs}} {{abbr|n.|neuter}} ('knee'). Each noun has the ending ''-ūs'' as a suffix attached to the root of the noun in the genitive singular form. The predominant letter in the ending forms of this declension is ''u'', but the declension is otherwise very similar to the third-declension ''i'' stems.

{| class="wikitable"
|+ Fourth declension paradigm
|-
! rowspan="2" |
! colspan="2" | ''-us'' ending nouns || colspan="2" | ''-ū'' ending nouns
|-
! Singular || Plural
! Singular || Plural
|-
! Nominative, Vocative
| -us || rowspan="2" | -ūs || rowspan="2" | -ū || rowspan="2" | -ua
|-
! Accusative
| -um
|-
! Genitive
| -ūs || -uum || -ūs || -uum
|-
! Dative
| -uī || rowspan="2" | -ibus<br>-ubus{{efn-lr|used only on bisyllabic words like {{wikt-lang|la|arcus}} and {{wikt-lang|la|artus}}.}} || rowspan="2" | -ū || rowspan="2" | -ibus
|-
! Ablative
| -ū
|-
! Locative
| -ī  || ''Dat.'' || -ī || ''Dat.''
|}

{{notelist-lr}}

{| class="wikitable"
! rowspan="2" |
! colspan="2" | {{wikt-lang|la|portus|portus, portūs}}<br /> port {{abbr|m.|masculine}}
! colspan="2" | {{wikt-lang|la|genu|genū, genūs}}<br /> knee {{abbr|n.|neuter}}
|-
! Singular
! Plural
! Singular
! Plural
|-
! Nominative, Vocative
|portus || rowspan="2" | portūs || rowspan="2" | genū || rowspan="2" | genua
|-
! Accusative
| portum
|-
! Genitive
| portūs || portuum || genūs || genuum
|-
! Dative
| portuī || rowspan="2" | portibus || rowspan="2" |genū || rowspan="2" | genibus
|-
! Ablative
| portū
|}

* In the genitive singular, ''cornūs'' may in later times be replaced by ''cornū''.
* The locative endings for the fourth declension are ''-ī'' (singular) and ''-ibus'' (plural); {{wikt-lang|la|senatus|senātī}} "at [the] senate", {{wikt-lang|la|domus|domī}} "at home".

====Domus====
{{wikt-lang|la|domus|Domus}} ('house, dwelling, building, home, native place, family, household, race') is an irregular noun, mixing fourth and second declension nouns at the same time (especially in literature). However, in practice, it is generally declined as a regular ''-us'' stem fourth declension noun, except for ablative singular ''-ō'', accusative plural ''-ōs'', and the use of the locative.<ref>[https://www.youtube.com/watch?v=33n1qYq9Liw The Fourth Declension] – tutorial by Ben Johnson of [https://latintutorial.com/about LatinTutorial]</ref>

{| class="wikitable"
! rowspan="3" |
! colspan="2" | {{wikt-lang|la|domus|domus, domūs/domī}} {{abbr|f.|feminine}}
|-
! colspan="2" | All possible declensions
|-
! Singular
! Plural
|-
! Nominative, Vocative
|domus ||domūs
|-
! rowspan="2" | Accusative
| rowspan="2" | domum || domōs
|-
|domūs
|-
! rowspan="2" | Genitive
| domūs || domuum
|-
|domī
|domōrum
|-
! rowspan="3" | Dative
| domuī || rowspan="6" | domibus
|-
|domō
|-
| rowspan="2" |domō
|-
! rowspan="2" |Ablative
|-
|domū
|-
! Locative
| domī
|}
{| class="wikitable"
! rowspan="3" |
! colspan="2" | {{wikt-lang|la|domus|domus, domūs}} {{abbr|f.|feminine}}
|-
! colspan="2" | Most common paradigm
|-
! Singular
! Plural
|-
! Nominative, Vocative
|domus ||domūs
|-
! Accusative
| domum || domōs
|-
! Genitive
| domūs || domuum
|-
! Dative
| domuī || rowspan="3" | domibus
|-
! Ablative
| domō
|-
! Locative
| domī
|}
{{notelist-lr}}