As a noun, “affect” is the way someone manifests emotion. Usually, the word appears in the context of a lack of affect, the non-emotion seen sometimes on the faces of criminals or traumatized victims.
Example: The detective observed that the suspect had a flat affect.
As a verb, “affect” can mean to fancy, cultivate, or feign. Here are some examples:
She affected a short, sleek hairstyle.
The student teacher decided to affect a scholarly manner.
Even though the businessman was from Ohio, he affected a British accent.
“Affect” can also mean to produce an effect or to act upon something. Because of this usage, people often confuse the word with “effect.” Here are some examples:
The dry air in the desert affected her skin.
The gloomy days and persistent rain affect his ability to concentrate at work.
Now let’s turn to “effect.” As a noun, “effect” is the outcome that results from a cause. It can also mean a particular mood that is created or a sound or image that imitates something real. When used with “in,” it can mean the state of being operative (“in effect”). The plural noun “effects” refers to movable personal property. Here are some examples:
One of the recession’s effects has been a credit crunch.
The cool colors in the painting create a calming effect.
The movie’s special effects were not convincing.
The new law goes into effect next month.
He’ll move his personal effects in a week.
“Effect” can also be used as a verb, and here again people become confused. As a verb, “effect” means to make something happen or to cause something that produces a desired result. Here’s an example: The lawyers worked together to effect a settlement.
According to Webster’s, the verb “affect” means to have an influence. In contrast, “effect” goes beyond influence to the actual achievement of an outcome. This table summarizes when to use “affect” and “effect.”