Jump to content

4th or u- Declension


Recommended Posts

3rd declension is a varied one, so I'm going to leave it for the time being. That's why I immediately skipped forward to 4th or u-declension and later on to 5th or e-declension.

4th or u-Declension

Nominative singular always ends on either -us (masculine nouns) or -u (neuter), and the base always ends on -u. There are only seven of feminine nouns in this declension and they follow masculine endings. The only difference is the form of adjective - they take feminine adjective.

                Sg                                                          Pl

N      fructus            genu                          fructus        genua

G      fructus            genus                        fructuum      genuum

D      fructui            genui                        fructibus        genibus

Acc    fructum          genu                          fructus          genua

V      fructus            genu                          fructus          genua

Ab    fructu              genu                          fructibus        genibus

Remember the rule of the neuter? It's followed here as well!


All neuter nouns have the same form for Nominative, Accusative, and Vocative. Also, in plural, these three end in -a!

There are several exceptions to D and Ab plural form. I'll name them here. The reason: to differ from the nouns which belong to 3rd declension and have the same -ibus ending, but about that more later:

                                    Dative/Ablative plural form

acus, acus, f - needle        - acubus  (instead of acibus)

arcus, arcus, m - arch      - arcubus (instead of arcibus)

lacus, lacus, m - lake        - lacubus (instead of lacibus)

quercus, quercus, f - oak  - quercubus (instead of quercibus)

specus, specus, m - cave  - specubus (instead of specibus)

artus, artus, m - extremity - artubus (instead of artibus)

partus, partus, m - birth    - partubus (instead of partibus)

Feminine nouns:

Idus, us, f - 15th day of the month    Idus Martiae - 15th of March

porticus, us, f - porch                    porticus alta - high porch

acus, us, f - needle                        acus acuta - sharp needle

manus, us, f - hand                        manus valida - strong hand

domus, us, f - home                      domus antiqua - old house

quercus, us, f - oak                        quercus umbrosa - shadowy oak

domus, us, f is the only noun which follows an exception!!

This is how you decline domus:

            Singular                      Plural

N          domus                      domus

G          domus                      domuum/domorum!!!

D          domui                      domibus

Acc        domum                      domos!!!

V          domus                      domus

Ab          domo!!                      domibus

Wherever you see exclamation marks, that's where you have to note the change. Domus is a noun which had taken half of the second declension. Ablative sg, Accusative Plural and optional G plural are from the second declension. The rest follows the pattern of fourth.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...