Usage Tip: Affect vs. Effect

This is perhaps one of the trickiest usage issues in the English language; but the cartoon above serves as an excellent memory device. But be careful: There are exceptions. Here's a simple, brief explanation from Grammar Girl:

The majority of the time you use affect with an a as a verb and effect with an e as a noun.

Affect
Affect with an a means "to influence," as in, "The arrows affected Ardvark," or "The rain affected Amy's hairdo." Affect can also mean, roughly, "to act in a way that you don't feel," as in, "She affected an air of superiority."

Effect
Effect with an e has a lot of subtle meanings as a noun, but to me the meaning "a result" seems to be at the core of all the definitions. For example, you can say, "The effect was eye-popping," or "The sound effects were amazing," or "The rain had no effect on Amy's hairdo."

Common Uses of Affect and Effect
So most of the time affect with an a is a verb and effect with an e is a noun. There are rare instances where the roles are switched, and I'll get to those later, but for now let's focus on the common meanings. This is "Quick and Dirty" grammar, and my impression from your questions is that most people have trouble remembering the basic rules of when to use these words, so if you stick with those, and you'll be right 95% of the time.

So, most of the time, affect with an a is a verb and effect with an e is a noun; and now we can get to the mnemonics. First, the mnemonic involves a very easy noun to help you remember: aardvark. Yes, if you can remember aardvark -- a very easy noun -- you'll always remember that affect with an a is a verb and effect with an e is a noun. Why? Because the first letters of "a very easy noun" are the same first letters as "affect verb effect noun!" That's a very easy noun. Affect (with an a) verb effect (with an e) noun.

"But why Aardvark?" you ask. Because there's also an example to help you remember. It's "The arrows affected Aardvark. The effect was eye-popping." It should be easy to remember that affect with an a goes with the a-words, arrow and aardvark, and that effect with an e goes with the e-word, eye-popping. If you can visualize the sentences, "The arrows affected the aardvark. The effect was eye-popping," it's pretty easy to see that affect with an a is a verb and effect with an e is a noun.

Rare Uses of Affect and Effect
So what about those rare meanings that don't follow the rules I just gave you? Well, affect can be used as a noun when you're talking about psychology--it means the mood that someone appears to have. For example, "She displayed a happy affect." Psychologists find it useful because they know that you can never really understand what someone else is feeling. You can only know how they appear to be feeling.

And, effect can be used as a verb that essentially means "to bring about," or "to accomplish." For example, you could say, "Aardvark hoped to effect change within the burrow."

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