effective
effective — 形容詞
1. bringing about the outcome someone wanted or hoped for, often in practical situa
有效的
能達到預期結果的
bringing about the outcome someone wanted or hoped for, often in practical situations where the approach actually works
The new marketing campaign was highly effective, bringing in hundreds of new customers.
新的行銷活動非常有效，吸引了數百名新客戶上門。
collocation: highly effective
Jessica found that a simple checklist was the most effective way to manage her daily tasks.
Jessica 發現，簡單的核對清單是管理日常任務最有效的方式。
pattern: effective way to + infinitive
This cleaning spray is effective against grease and oil stains on kitchen surfaces.
這款清潔噴霧對廚房檯面上的油漬和污垢很有效。
Hamza's calm voice was an effective tool for settling arguments among the children.
Hamza 冷靜的聲音是平息孩子們爭吵的有效工具。
The company needs a more effective strategy for reaching younger buyers online.
這家公司需要用更有效的策略來接觸網路上年輕的消費者。
- successful
broader — focuses on achieving a positive outcome, often after effort
- productive
emphasises producing a large amount of output or results
- useful
simpler and less formal; describes something that helps in a practical way
- ineffective
direct opposite — failing to produce the desired result
- useless
stronger and more informal — completely unable to produce any good result
文法句型
effective + noun
effective at/in + noun/gerund
effective against + noun
用法筆記
Frequently modified by adverbs such as 'highly', 'very', 'remarkably', 'equally', 'less', or 'more'. The opposite is 'ineffective'. Do not confuse with 'efficient' — an effective method produces the desired result; an efficient method produces the desired result with the least waste of time or effort.
常見錯誤
2. (of a medical treatment or drug) found to produce good results in ordinary use b
實效的
在真實使用中證實有效的
(of a medical treatment or drug) found to produce good results in ordinary use by the general public, not just in strictly controlled lab experiments
Doctors are studying whether this new drug is effective in real-world patients outside of clinical trials.
醫生們正在研究這種新藥在臨床試驗以外的一般病人身上是否有效。
pattern: effective in + noun phrase (patient group)
The vaccine proved effective among elderly populations in rural parts of the country.
該疫苗在該國鄉村地區的老年族群中被證實有效。
pattern: effective among + population group
The treatment worked well in the lab but was less effective on actual patients with other health conditions.
這種療法在實驗室中效果很好，但用在有其他健康狀況的實際病人身上效果就沒那麼好。
Obi asked his doctor how effective the new medicine would be for his particular condition.
Obi 問醫生，新藥對他特定的病情會有多有效。
- efficacious
more formal; means proven to work in controlled scientific tests rather than real-world use
- ineffective
failing to produce the desired medical result in real-world use
文法句型
effective in + noun/gerund
effective among + group
effective for + noun
用法筆記
This sense is primarily used in medical and pharmaceutical contexts. It contrasts with 'efficacious', which means the treatment works under strictly controlled conditions (efficacy). 'Effective' in this sense means it works in real-world use (effectiveness).
3. having a real effect or position in practice, even though this is not the offici
實際的
雖非正式但實際存在的
having a real effect or position in practice, even though this is not the official or legal situation
Although Tamar had no official title, she was the effective leader of the entire research team.
雖然 Tamar 沒有正式頭銜，但她是整個研究團隊實際上的領導人。
pattern: effective + role/title (de facto meaning)
The ceasefire brought an effective end to the fighting, even though no peace treaty was ever signed.
停火協議實際上終止了戰鬥，儘管從未簽署和平條約。
After the founder retired, his daughter became the effective head of the family business without any formal announcement.
創辦人退休後，他的女兒在沒有任何正式公告的情況下，成了家族企業實際上的負責人。
The old regulations were never officially removed, but they are no longer effective in practice.
舊規定從未正式廢除，但在實務上已不再有效。
文法句型
effective + noun (role/status/control)
用法筆記
Used only before a noun (attributive position). Common in formal, legal, and political writing. Often interchangeable with the Latin phrase 'de facto', which is used similarly in English.
常見錯誤
4. (of a law, rule, agreement, or official decision) starting to operate legally an
生效的
正式開始適用的
(of a law, rule, agreement, or official decision) starting to operate legally and be put into practice
The new parking regulations become effective on the first of March, so mark your calendar.
新的停車規定將於三月一日起生效，請在日曆上標記下來。
collocation: become effective on + date
Padma was told that her health insurance would be effective from the day she submitted the application form.
Padma 被告知，她的健康保險從她提交申請表的那天起生效。
collocation: effective from + date/event
The court's ruling will remain effective for the next three years unless an appeal changes it.
除非上訴推翻，否則法院的判決在未來三年內仍然有效。
Once the agreement is signed by both parties, the new terms become immediately effective.
協議經雙方簽署後，新條款立即生效。
文法句型
become effective
effective from + date
effective on + date
remain effective
immediately effective
用法筆記
Almost always used predicatively (after 'become', 'remain', 'be'). Common in official announcements, contracts, and legal documents. The phrase 'effective immediately' is a fixed expression used in formal notices of policy changes.
常見錯誤
effective — 名詞
1. a person or thing that is able to produce a desired result, especially in a mili
有效者
能發揮作用的人或事物
a person or thing that is able to produce a desired result, especially in a military or organizational context where capable members are counted separately
The general reviewed his troops and counted only three thousand effectives ready for the mission.
將軍檢閱了他的部隊，算出只有三千名有效兵員可出任務。
military context: count + effectives
The committee needs to identify the effectives in the group — those who can actually get the work done.
委員會需要找出團隊中真正能做事的人——那些確實能完成工作的人。
Out of fifty volunteers, only twenty were effectives who could be relied upon in an emergency.
五十名志願者中，只有二十名是緊急時刻可以信賴的有效人力。
During the war, the unit lost half its effectives in the first month of fighting.
戰爭期間，該單位在第一個月的戰鬥中就損失了一半的有效兵員。
- operative
a person who works effectively, especially in military or intelligence contexts
文法句型
the effectives
effective in + noun phrase
用法筆記
Very rare in modern English. Most commonly appears in historical military contexts referring to soldiers available for duty. Learners at CEFR C2 may encounter this in older texts but should generally use 'effective' as an adjective.