improper

Compared meaning: not suitable or not proper for a situation (adjective).

比较义项：不适当的，不合适的（形容词）。

• inappropriate

  The neutral, everyday choice; describes something mismatched with the situation, tone, or audience, without implying a broken rule.

  更中性、日常的用词；表示某事与场合、语气或对象不匹配，并不一定意味着违反了规则。

  Cracking jokes at the funeral felt deeply inappropriate to everyone present.

  在葬礼上开玩笑，在场的每个人都觉得非常不合适。

• improper 本词

  Slightly more formal and stronger; often suggests a breach of correct standards, rules, or etiquette rather than a simple mismatch.

  语气稍正式、更强烈；常暗示违反了正确的标准、规则或礼节，而不只是简单的不匹配。

  Using company funds for personal trips is considered improper conduct.

  把公司资金用于个人旅行被认为是不正当的行为。

Inappropriate and improper both mean not suitable for a situation. Inappropriate is the neutral, everyday choice, describing something mismatched with the situation, tone, or audience. Improper is slightly more formal and stronger, often suggesting a broken rule or standard of behavior, not a simple mismatch.

这两个词都表示某事不符合特定场合的要求，但 improper 语气更重，常隐含违反规范或礼节，有时更正式；inappropriate 更中性、更常用，多指与场合不匹配。