Learn Hardcore Latin: Discipula cum ea in villa manet. - The female student stays with her in the villa.

Because “discipula” is the subject of the sentence. In Latin, the subject usually appears in the nominative case, and here it refers to the female student who is performing the action of remaining.

What role does “cum ea” play in the sentence?

“Cum ea” is a prepositional phrase. “Cum” means “with,” and “ea” here is the ablative singular pronoun meaning “her” or “that woman.” Together, they specify that the female student is remaining with her (this other female person).

Why is “in villa” in the ablative case?

In Latin, the preposition “in” can take either the ablative or the accusative, depending on context. When it indicates location (remaining in or on somewhere), it’s followed by the ablative. Hence “in villa” means “in/at the house” in the sense of being inside or at that place.

Why does “manet” end with -et?

“Manet” is the third-person singular present active indicative form of the verb “manēre” (to remain). The -et ending is standard for third-person singular in the present tense for verbs of the second conjugation. It means “he/she/it remains” or “he/she/it stays.”