B1
efficient vs effective
Effective means it works and gets the result you want; efficient means it works without wasting time, money or energy. A medicine is effective; a machine is efficient.
The difference
| Word | Meaning | Goes with | Example |
|---|---|---|---|
| efficientadjective/ɪˈfɪʃ.ənt/ | Meaning working well and quickly without wasting time, money or energy | Goes with energy-efficient | Example The new machine is more efficient: it does the same work with half the electricity. |
| effectiveadjective/ɪˈfek.tɪv/ | Meaning working well and producing the result you want | Goes with effective treatment | Example This medicine is very effective against headaches. |
Which word fits?
1 of 8Pick the word for the gap. Its form may change in the sentence.
The vaccine is 90 percent at preventing serious illness.