SINGULAR. 
CASES.                  MEANINGS.             TERMINATIONS.
Nom.  porta      a gate (as subject)         -a
Gen.  portae     of a gate                   -ae
Dat.  portae     to or for a gate          -ae
Acc.  portam     a gate (as object)          -am
Voc.  porta      O gate!                     -a
Abl.  porta      with, by, from, in a gate   -a

PLURAL.
Nom.  portae     gates (as subject)          -ae
Gen.  portarum   of gates                    -arum
Dat.  portis     to or for gates           -is
Acc.  portas     gates (as object)           -as
Voc.  portae     O gates!                    -ae
Abl.  portis     with, by, from, in gates    -is

1.  The Latin has no article, and porta may mean either a gate or the gate; and in the Plural, gates or the gates.

Peculiarities of Nouns of the First Declension.

21. 1.  EXCEPTIONS IN GENDER.  Nouns denoting males are Masculine; as, nauta, sailor; agricola, farmer; also, Hadria, Adriatic Sea.

2.  Rare Case-Endings,—­

a) An old form of the Genitive Singular in -as is preserved in the combination pater familias, father of a family; also in mater familias, filius familias, filia familias.  But the regular form of the Genitive in -ae is also admissible in these expressions; as, pater familiae.

  b) In poetry a Genitive in -ai also occurs; as, aulai.

  c) The Locative Singular ends in -ae; as, Romae, at Rome.

  d) A Genitive Plural in -um instead of -arum sometimes occurs; as,
  Dardanidum instead of Dardanidarum.  This termination -um is not a
  contraction of -arum, but represents an entirely different case-ending.

e) Instead of the regular ending -is, we usually find -abus in the Dative and Ablative Plural of dea, goddess, and filia, daughter, especially when it is important to distinguish these nouns from the corresponding forms of deus, god, and filius, son.  A few other words sometimes have the same peculiarity; as, libertabus (from liberta, freedwoman), equabus (mares), to avoid confusion with libertis (from libertus, freedman) and equis (from equus, horse).

Greek Nouns.

22.  These end in -e (Feminine); -as and -es (Masculine).  In the Plural they are declined like regular Latin nouns of the First Declension.  In the Singular they are declined as follows:—­

Archias,           Epitome,           Cometes, comet.
Archias.         epitome.
Nom.  Archias            epitome            cometes
Gen.  Archiae            epitomes           cometae
Dat.  Archiae            epitomae           cometae
Acc.  Archiam (or -an)   epitomen           cometen
Voc.  Archia             epitome            comete (or -a)
Abl.  Archia             epitome            comete (or -a)

1.  But most Greek nouns in -e become regular Latin nouns in -a, and are declined like porta; as, grammatica, grammar; musica, music; rhetorica, rhetoric.