effective

Compared meaning: starting to have legal force (adjective).

比较义项：（开始）生效的，具有效力的（形容词）。

• effective 本词

  The everyday, general word for something starting to apply or take legal force, especially paired with a date ("effective from", "effective immediately"); used for laws, policies, prices, in both formal and casual English.

  effective是日常、通用的词，指某事物开始生效或具有约束力，常与日期搭配使用（如“从……起生效”“立即生效”），可用于法律、政策、价格等场合，正式和口语皆可。

  The new pricing policy is effective starting next Monday.

  新的定价政策从下周一起开始生效。

• operative

  More formal and legal in tone, used mainly for laws, treaties or clauses becoming legally binding; it sounds stiff and technical, and would feel out of place in casual conversation.

  operative语气更正式、更具法律色彩，主要用于法律、条约或条款开始具有约束力，听起来生硬、专业，用于日常口语会显得不自然。

  The clause becomes operative only after both parties sign the contract.

  该条款只有在双方签署合同后才开始生效。

Effective and operative both describe a law starting to apply. Effective is the everyday word, often paired with a date, as in 'effective immediately'. Operative is more formal and legal, mainly for laws becoming binding. Effective's common meaning is not compared here.

这两个词都可以指法规、政策或条款开始生效或具有约束力，但语气和使用场合不同：effective更通用、更口语化，operative更正式、偏法律用语。这里不比较effective常见的“有效的，能产生预期效果的”义项（如an effective method），也不比较operative作名词时“特工，密探”的义项。