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 'effect' 'affect' and 'efficient' 'effective'

Warda Jamal from Pakistan asks:

I always get confused in the usage of effect and affect. Please give examples of their use in sentences.

Kisy Kesh from Guadaloupe writes:

I’m 16 and I’ve been studying English for a few years now. I’d like to know the difference between efficient and effective and the way to use them.


Roger replies:more questions

affect – effect

Affect and effect are often confused, Warda, even by native speakers of English. The most important thing to remember is that affect is used as a verb and effect is normally used as a noun. When they are used in this way, they are similar in meaning, signifying ‘influence’, ‘impact’ or ‘change’. Compare the following:

  • 'The really hot weather affected everybody’s ability to work.'

  • 'I know my neighbours play loud music late at night, but that doesn’t affect me.I can sleep through anything.'

  • 'The number of tourists travelling to Britain this year has not been affected by the strength of the pound.'

  • 'The tablets which he took every four hours had no noticeable effect on his headache.'

  • 'My words of comfort had little effect. She just went on crying and wouldn’t stop.'
Note: we talk about someone or something having an effect on something or someone. If we use effect as a verb, it means to ‘carry out’ or to ‘cause something to happen’, but it is used only in very formal English. Consider the following:
  • 'Repairs could not be effected because the machines were very old.'

efficient – effective

These two qualitative adjectives are often confused, Kisy. If somebody or something is efficient, then he, she or it works in a well-organised way, without wasting time or energy. Consider the following examples:

  • 'She was efficient in everything she did and was frequently commended for exemplary service to the organisation.'

  • 'He hasn’t made very efficient use of his time in revising for these exams: he has made no notes and his concentration spans appear to last for no longer than ten minutes.'

  • 'This engine is really efficient, it can run for 30 km on only 1 litre of fuel.'
If something is effective, it works well and produces the results that were intended. Consider the following examples:
  • 'These tablets really are effective. My headache’s much better now.'

  • 'The only effective way to avoid hay fever at this time of the year, if you are a sufferer, is to stay indoors.'

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