efficient

Definitions

ef- (out) + fic (weakened fac, 'do') + -ient = 'doing the work out (to full effect).' The vowel weakening is on display: facere's a becomes i. Where effective just means 'it works,' efficient adds 'and it does so without waste' — maximum result, minimum input.

Why It Means This

Efficient is one of the clearest examples of fac's vowel weakening: the everyday word factory shows fac plainly, but bury that root under the prefix ef- and the a slides to i — fic. The meaning, though, is intact: an efficient process gets the result 'done out' cleanly, with nothing wasted along the way.

Common Collocations

• 1.highly efficient非常高效
• 2.energy efficient节能的
• 3.efficient use of高效利用……
• 4.fuel efficient省油的
• 5.cost efficient成本高效的

Example Sentences

• 1.

  The new system is far more efficient than the old one.

• 2.

  She's an efficient worker who never wastes time.

• 3.

  These appliances are designed to be energy efficient.

Easily Confused

efficient vs. effective: efficient is about HOW (no waste); effective is about WHETHER (it works at all). You can do the wrong task very efficiently — fast and cheaply, but it still doesn't get you the result you wanted.