affect/effect
“This woman practiced gratitude for a year and was stunned by how it effected her health.”
—Business Insider
“The recent roller coaster weather has had an affect on wildlife in the area.”
—Fox11online.com
Affect and effect are two of the most commonly confused words — and those examples above demonstrate the mistake that so often happens.
In each case, it should have been the opposite. According to Barron’s, one of the largest SAT preparation courses, switching effect and affect is one of the most common errors students make . . . and it’s not only students getting confused. So let’s effect a change and correctly affect our speech.
Affect is almost always a verb meaning “to act upon, to make a change to something.” The first example above should say that the woman “was stunned by how it affected her health.” On the other hand, effect is usually a noun, and typically means “a change that resulted from something else acting on it.”
Nice and neat . . . except that, as is so often the case with English, it gets a little more complicated (and annoying). Affect can also be used as a noun (most commonly in psychiatry, meaning an emotional response or state, as in “a flat affect”), and effect can be used as a verb, meaning to cause a change to something.
With all this confusion between affect and effect, you’d think they both probably came from the same old root words, but they probably didn’t. Affect mostly likely comes from the Latin, afficere, meaning “to treat, to afflict.” It was often used in a negative sense in early English, as in being affected or afflicted with some disease. Effect probably comes another Latin word, efficere (to accomplish). Along the way from Latin through French to English, the two words and their derivations got tangled up in use and meaning, all to a bad effect today.
affect (v): to have an effect on
effect (n): a change caused by actions; (v): to cause something to happen