The words affect and effect are confused by many people, even adults. Do you know which of the following sentences is correct?
Polly's hay fever affected her performance in the exam.
Polly's hay fever effected her performance in the exam.
The first sentence is the correct one. The word affect is a verb meaning 'to produce a change in something'. The word effect is a noun and means 'a result'.
The medication had an instant effect on her headache.
(The word effect can also be used as a verb, meaning 'to cause' or 'to bring about', as in 'the criminal effected his escape by vaulting the wall', but this usage is quite technical and is mostly found in official reports.)
In this worksheet you can practise using the words affect and effect correctly.