effective
gb/ɪfˈɛktɪv/ us/ɪfˈɛktɪv/
B1
English
~ 1100
Senses
0 senses
adjective
B1
property
1
Producing the desired result
Able to produce the result you want.
Usage pattern:
[something] is effective at [doing something]
Common mistake:
Learners sometimes confuse 'effective' with 'efficient'. 'Effective' means it works well, while 'efficient' means it works well with little waste.
Synonyms
successful (Emphasizes achieving a goal, sometimes with broader scope than 'effective'.)
|
efficient (Focuses on achieving results with minimal waste of time or resources.)
Antonyms
ineffective (Direct opposite; fails to produce the intended result.)
|
useless (Stronger and more negative; of no practical use.)
Collocations
highly effective
|effective method
|effective strategy
|effective communication
|effective treatment
Themes
business
|daily life
|problem solving
|core_vocabulary
|work
Examples
- This new medicine is highly effective against the virus.
- The training program was effective in improving staff performance.
- Her speech was effective in changing public opinion.
- Regular exercise is effective at reducing stress.
- The new policy proved effective after just a few weeks.
Learner examples
- The new rules are effective in schools.
- This cream is effective for dry skin.
- Exercise is effective for good health.
- The plan is effective and easy to follow.
adjective
formal
B2
property
2
In operation from a given time
Starting to be used or done from a certain time.
Usage pattern:
effective [date/time]
Common mistake:
Learners may confuse this meaning with 'effective' meaning 'good at producing results'; here it refers to the start of official use.
Synonyms
operative (More technical/legal term for being in force.)
Antonyms
expired (No longer valid or in effect.)
Collocations
effective immediately
|effective date
|effective from
|effective as of
Themes
law
|business
Examples
- The new law will be effective from January 1st.
- The changes are effective immediately.
- Her promotion is effective as of next Monday.
- The policy becomes effective upon signature.
Learner examples
- The rule is effective today.
- My new job is effective next week.
- The law is effective from May 1.
adjective
formal
C1
property
3
Existing in fact, not formally recognized
Real or true in fact, even if not official.
Synonyms
actual (Emphasizes real existence regardless of formal status.)
Antonyms
nominal (Refers to something existing in name only without real power or effect.)
Collocations
effective leader (de facto)
|effective control
|effective power
Themes
law
|politics
|core_vocabulary
Examples
- He is the country's effective ruler, though not elected.
- They have effective control over the region.
- She became the effective head of the department after her boss resigned.
Learner examples
- She is the effective boss here.
- He has effective control of the team.
- They are the effective leaders now.
Grammar
Dictionary form
effective
IPA
GB/ɪfˈɛktɪv/
US/ɪfˈɛktɪv/
Syllables & stress
ef - fect - ive (3 syllables)
Stress on 2nd syllable (fect)
Word forms
Adjective
- Base: effective
Word family
Core family
Negative and opposite forms
Expressions
effective date
1/ɪfˈɛktɪv dˈeɪt/
fixed phrase
formal
Official start date of something
The day when something starts to be used or done by law or rule.
Examples
- The contract's effective date is July 1st.
- Check the policy's effective date before signing.
effective immediately
1/ɪfˈɛktɪv ɪmˈidiɪtli/
fixed phrase
formal
Starting now without delay
Starting right now, without waiting.
Examples
- Your suspension is effective immediately.
- The price increase is effective immediately.