Choosing between affect and effect can be scary. Think of Edgar Allen Poe and his RAVEN: Remember Affect Verb Effect Noun. You can't affect the creepy poem by reading it, but you can enjoy the effect of a talking bird.
In everyday speech, affect is a verb. It means to influence something, such as in the headline from the Albuquerque News,
Downed Power Line Affects PNM Customers
The downed power line had an impact on some power customers: they were without electricity overnight.
Effect is mostly commonly used as a noun meaning the result or impact of something, an outcome. If there's "a/an/the" in front of it, it's an effect. The second sentence is from a story about the outcome of long-term sleeping trouble,
The Effect of Persistent Sleepiness
Adding to the confusion, effect can also be used as a verb to mean to produce or to cause to come into being. Here's an example that uses it correctly,
A government unable to effect any change is a government that will produce no surprises.
Put another way, a government that can't produce change won't be able to produce surprises; it will be predictable.
Most of the time, you'll want affect as a verb meaning to influence something and effect for the something that was influenced. The difference between affect and effect is so slippery that people have started using "impact" as a verb instead. Don't be one of them! Another trick is to remember that affect comes first alphabetically, and an action (to affect) has to occur before you can have a result (an effect).
Affect is most often used as a verb meaning “to have an impact on,” as in “The tornado barreling towards us will affect our picnic plans.”Continue reading...
As a noun, effect describes an appearance or impression that’s created on purpose, such as the dramatic effect of the bright red walls in your kitchen, or sound effects from your favorite movieContinue reading...