Possession with genitive

To show that something belongs to someone, Latin uses a special case called the genitive. Where English says "the girl's book" or "the book of the girl", Latin puts the owner into the genitive and leaves the possessed thing alone. Recognizing the genitive ending is one of the fastest ways to make sense of a Latin phrase.

The typical singular genitive endings for the first two noun groups are -ae and -i:

Noun	Genitive	Meaning
puella (girl)	puellae	of the girl / the girl's
servus (slave)	servi	of the slave / the slave's
Roma (Rome)	Romae	of Rome

Examples: Liber puellae - the girl's book. Villa domini magna est. - The master's house is big. Muri Romae - the walls of Rome.

For English speakers: there is no apostrophe and no fixed word for "of" - the ending does the whole job, so puellae already means "of the girl". Watch the word order, which is the reverse of the English "'s" pattern: Latin usually says liber puellae, literally "book of-the-girl". And be careful, because -ae is doing double duty here: puellae can mean "of the girl" (genitive) or "the girls" (plural subject), so let the rest of the sentence tell you which.