Subjects and Objects
There is an old saying that the headline “Dog Bites Man” is not news. “Man Bites Dog” is news. The humor in this relies on knowing who sunk teeth into whom. Or, in grammatical terms, which is the subject and which is the object. The biter is the subject of the verb. The one on the receiving end (ouch!) is the object, or, more precisely, the direct object.
English is an analytical language. It shows subjects and objects by their position in a sentence. In essence, there are slots where words can be plugged in: subject-verb-direct object. Whatever fills the first slot, be it dog or man, performs the action. Whatever fills the slot after the verb receives the action. In English, that's how news is made.
But Latin is an inflected language. Subjects and objects are determined by case endings. Nominative case endings show the subject, regardless of a noun's position in a sentence. Accusative case endings show the object.
Word order in Latin is usually subject-object-verb. But it doesn't have to be in that order. If this order changes, the emphasis shifts. Vir canem mordet (“man bites dog”) is normal word order. It answers the question “Who bites dog?” (Man.) Canem vir mordet still means “man bites dog” (same case endings), but it answers the question “What does man bite?” (Dog.)
