5th or e-declension

[AureliaeLacrimae]

Some general rules that nouns belonging to this declension follow are: Nominative singular always ends on -es (no exceptions here), genitive singular ends on -ei and the base ends on long -e.

I'll use dies and res for examples

Base: die-                re-

          (di- as in disaster and e- as in elephant)

              Singular                                Plural

N      dies            res                        dies        res

G      diei            rei                      dierum      rerum 

D      diei            rei                      diebus      rebus

Acc    diem          rem                    dies          res

V      dies            res                      dies          res

Ab    die              re                      diebus      rebus

Some interesting pieces of information about the quality of the vowel:

In the genitive ending -ei, the e is long if a vowel stands before him, e.g. diei; and short if it's a consonant, e.g. fidei (from the noun fides, loyalty)

Only two nouns have full declension!!!!

These are dies and res. All other are only partially declined. They have singular forms and some or none forms in plural! These are:

- Acies (sharpness), spes (hope), species (sight, view) have only nominative, accusative and vocative plural.

- The rest have only singular and are mostly abstract, such as fides, fidei, f - loyalty, faith

All of the nouns of this declension are feminine with the exception of two - dies, ei, m - day and meridies, ei, m noonday/noon/noontide. The noun dies can also stand in singular and be feminine, but then it doesn't mean day, it means deadline or a specific determined date!!

e.g.

dies festus - a holiday (any holiday, it doesn't matter whether it's Saturnalia, Veneralia or any other - no specific determination since Romans had about 100 days for state holidays)

dies constituta - a set date (for example, for court meeting of a certain case and such - you know exactly which day it is! and it's only in those specific circumstances)

meridies calidus - a warm noon

There aren't many nouns which belong to this declension. Some common are:

dies, ei, m day ; dies, ei, f deadline

res, ei, f thing

meridies, ei, m noon

fides, ei, f loyalty, faith

spes, ei, f hope

acies, ei, f sharpness

glacies, ei, f ice

species, ei, f sight, view

eluvies, ei, f flood

facies, ei, f face

series, ei, f series, row

luxuries, ei, f luxury, extravagance

It may seem like much, but I'd named most of the nouns belonging into this group, so it isn't really. The rest aren't so common, so they aren't of great importance to us.

I'd also found an interesting PDF page online and I'd attached it. You can use it when learning, it may be useful.

These nouns also take adjectives of 1st and 2nd declension. The only rule you have to follow is gender! So, bona fides (good faith) would be

N    bona fides

G    bonae fidei

D    bonae fidei

Acc  bonam fidem

V    bona fides

Ab  bona fide

Bona follows the 1st feminine declension rules and fides 5th declension. It may get a little confusing, but you'll get used to it.

For practice:

mala spes

pulchra species

magna glacies