Affect or effect?
Both of these words are verbs and nouns and their meanings overlap. Very confusing! This slippery duo can send even experienced writers into a spiral of uncertainty. Especially, since many people pronounce them in almost the exact same way.
Here’s a basic guideline for affect vs effect: Generally, we use affect as a verb (an action word) and effect as a noun (an object word).
What does affect mean?
The verb affect means “to act on; produce an effect or change in” as in, “the cold weather affected the crops,” (it produced a change in the crops . . . probably killing them). It can also mean “to impress the mind or move the feelings of,” as in “The music deeply affected him,” (the music changed his feelings or thoughts). So, when you’re looking to use one of these two terms to express an action, chances are you’re looking for affect.
Affect can be a noun when used to describe emotion in a psychological context. (Example: “A sad affect may be a symptom of depression.”)
What does effect mean?
Effect is most commonly used as a noun, meaning “result” or “consequence.” So, when you’re writing, try to swap out effect for result and see if it makes sense. For example, “his sunburn was an effect of exposure to the sun.”
Effect might also catch you off guard because it appears in two common idioms: in effect, and take effect. It can also be a verb meaning “make happen,” but that use is less common. (Example: She effected her test score by studying hard.)
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Affect vs. Effect: What caused all the confusion?
Want to go deep? Much of the confusion surrounding this pair is due to a shared linguistic ancestor. Both words have roots in the Latin verb facere meaning “to do, make.” Affect derives from the Latin verb afficere meaning “to do something to, to have influence on.” Effect descends from the Latin verb efficere, “to make, carry out.”
Sticking to the basic guideline of effect as a noun and affect as a verb will generally keep you in the clear.