I'm sure there are Chinese words that can serve the same purpose. The point is that they aren't mandatory.

So, to an English learner coming from these languages, a sentence like "I was cleaning attic and found book" is perfectly understandable. Exactly what attic and what book we're talking about should be apparent from context.

On the other hand, in actual English, "I was cleaning the attic and found a book" portrays a different picture from "I was cleaning an attic and found the book." Use one when the other is warranted, and it sounds weird and confusing.