While `费用` is a practical, everyday term, its usage touches upon the pragmatic nature of Chinese culture regarding finances. Discussing costs, expenses, and getting good value is very common and not considered rude. A key cultural difference lies in its breadth compared to English. In English, we distinguish sharply between a “fee” (for a service, like a lawyer's fee), a “cost” (the total amount for a project or item, like the cost of building a house), and an “expense” (often in a business or budgeting context, like travel expenses). `费用` acts as a large umbrella covering all these concepts. You can use it for `学费` (tuition fee), `生活费用` (living costs), and `出差费用` (business trip expenses). This reflects a more holistic view of expenditure. For a learner, this is actually a simplification: when in doubt about what word to use for money being paid out, `费用` is often a safe bet.
`费用` is used constantly in both formal and informal situations. It often combines with other words to specify the type of cost.
The connotation is neutral. It's simply a factual term for money that needs to be paid.
The most common mistake for learners is confusing `费用`, `价格`, and `成本`.
Think of it this way: A factory has a `成本` (cost) to make a phone. They sell it to a store, which puts a `价格` (price) on it. You buy it, and for you, the money you spent is part of your monthly `费用` (expenses).