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Affect vs Effect


  • ‘Affect’ (verb) means ‘have an effect on, or make a difference to something’.
  • ‘Effect’ (verb) means ‘cause something to happen’.

What’s the difference between ‘affect’ and ‘effect’?

‘Affect’ and ‘effect’ are very commonly misused in academic texts due to their similar spellings, but they have different meanings:

  • While ‘affect’ refers to the influence or effect that something (e.g. a given factor) has on something else (e.g. results), ‘effect’ refers to something being brought into existence by someone (most often) or something.
  • ‘Affect’ is frequently used in scientific research, in the context of assessing the influence of factors on a given outcome.
  • Used as a noun, ‘effect’ is also very frequently used in the same context. But as a verb, it is used primarily in the context of implementing policy changes, measures, a new law, etc.

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How they’re used

Example sentences with ‘affect’

  • Sunlight exposure affects vitamin D production.
  • The report showed that highway construction strongly affected the area.

Example sentences with ‘effect’

  • A duty of the legislature is to effect the will of the citizens.
  • The transfer of a business is effected by the law of the country in which the business is located.