Meaning and Usage
"无效" means "invalid" or "ineffective." It describes something that does not produce the intended effect or is legally or practically useless. It is often used in formal contexts such as legal documents, passwords, or explanations.
Common Collocations
- 无效密码 (invalid password): used when a password does not work.
- 法律无效 (legally invalid): used to describe contracts or agreements without legal effect.
- 无效解释 (ineffective explanation): when an explanation fails to convince.
Usage Notes
"无效" is an adjective and can be used to describe both tangible things (like a ticket or password) and intangible things (like arguments or explanations). It is more formal than synonyms like "没用" (useless) and often appears in official or written language.
Avoid confusing "无效" with "无用"; the latter emphasizes uselessness in a broader sense, while "无效" focuses on lack of effect or validity.