Latin Genitive Singular

When you are trying to translate a Latin noun into English or English into Latin, you should know which of the five declensions the noun falls into. If you know the declension and the dictionary forms of a noun, you're set. For instance, the word puella, a first declension word that will be listed as "puella, -ae, f." or something similar in the dictionary, is feminine (that's what the "f." stands for; m. stands for masculine and n. stands for neuter) and is first declension, as you can tell from the second part of the dictionary listing, here; "-ae".

The genitive is the name for this second form ("-ae" for the first declension) and is the equivalent of a possessive or apostrophe-s case in English.

There are five declensions in Latin. The genitive ending is used in the dictionary because each of the five declensions has its own genitive form. The five genitive terminations are:

1. -ae
2. -i
3. -is
4. -us
5. -ei

An example from each of the 5 declensions:

1. puellae - the girl's (puella, -ae, f.)
2. servi - the slave's (servus, -i, m. Note: the "o" of this declension does not show up in the genitive)
3. principis - the chief's (princeps, -ipis, m.)
4. cornus - the horn's (cornu, -us, n.)
5. diei - the day's (dies, -ei, m.)

Note - the long mark (macron) is missing. It belongs on the i of the genitive singular in the second and fifth declensions. This genitive is the genitive singular. There is also a genitive plural that can be figured out based on the number of the declension (1-5).