The accusative

The accusative has two essential values, first as direct-object complement and second, the extension of the action through space and time. Italics note the accusative including any preposition.

direct-object complement:
Romulus condidit Romam. (Romulus founded Rome.)
 
Romam is the direct object of the verb, condo (I establish).
 
extension of space and time:
In Italiam Aeneas peruenit. (Aeneas reached Italy.)
 
Intactum multos annos intactum permansit Forum. (The Forum survived whole for many years.)
 
Romulus multos annos regnauit. (Romulus ruled for many years.)