* "Garbage" itself is a mass noun, meaning it refers to a general, uncountable quantity. It's like "water" or "sand".
* We use "pieces of garbage" or "items of garbage" if we need to specify individual units.
For example:
* Incorrect: The garbage were overflowing.
* Correct: The garbage was overflowing.
* Correct: The pieces of garbage were overflowing.
Let me know if you have any other grammar questions!