Affect or Effect

Although this is probably one of the most confusing problems in grammar, the concept behind their differences is quite simple. Affect is a verb and effect is a noun. The problem is that both of these words look similar, and have similar meanings. There are also many exceptions to the normal usages, which makes understanding affect and effect much more difficult.

Another way to figure out which verb to use is to look at the derivation of each word. Affect is derived from affectus which means “to do something to, act on”. Effect , from efficere, means “to bring about”. ‘To do something’ and ‘to bring about’ are very similar definitions. More modern definitions of these words say that affect means ‘to influence’ and effect means ‘ a result’. Now when thinking about putting each into sentences we can now think back to whether it is a noun or verb and compare their definitions.

Example:

1)      The rain had no effect on her hair

2)      The rain had no affect on her hair

Which of the above sentences uses the correct for of affect/effect? First we must think whether it is a noun or a verb. In the above sentence ‘had’ is the verb.  Effect is then the object of the sentence. ‘On her hair’ is a prepositional phrase, and not the object of the sentence. Therefore the correct choice is the first sentence. Another way to test is to loosely insert the definitions in the sentence. There was no change in her hair as a result of the rain.

Example:

1)      The botched lobotomy effected her personality negatively

2)      The botched lobotomy affected her personally negatively

In the above sentences affect/effect is being used as a verb. The botched lobotomy is the subject and her personality is the direct object. This leaves effect/affect as the sentence’s verb. If we put the definition of affect into the sentence then we have – ‘the botched lobotomy’ had an influence on ‘her personality’. Therefore sentence 2 is correct by using affect , the verb.

Although there are many inconsistencies and exceptions to the above rules, I hope that these rules can lay a general framework to figuring out which of these words to use when you are faced with a grammar predicament.

Here is some further help from theoatmeal.com: