"The elephant eats bread."
Translation:Fil ekmek yer.
"Fil" is the agent in this sentence, it's doing the eating, so it's not the accusative word. (There isn't a word in accusative form in this sentence.)
Turkish accusative words take "the" in English translations in order to indicate that they're accusative. However not all English words with the article "the" before them indicate accusative case in Turkish. It's due to grammar that non-accusative English words have the before them.
For example "Fil ekmek yer-The elephant eats bread." Elephant needs the article before it to be correct in English grammar.
"Fil ekmeği yer-The elephant eats the bread" here you see the accusative "ekmeği" and how the article indicates a specific bread, rather than any bread.