"I eat half of the bread."
Translation:Tôi ăn nửa cái bánh mì.
"Ổ" means "loaf", as in "a loaf of bread". Usually I don't use it, and neither to people around me, but I saw it in books.
"You used the wrong word. Tôi ăn một nửa ổ bánh mì." Goofy message for not using "cái".
I think the use of "of" in this sentence should be optional. In the US you can just say "I eat half the bread..." if you're talking about a specific known quantity during a specific timeframe. "Of" becomes optional in casual speak. E.g. I eat half the bread in the morning and half at night.