Every time I write either “affect” or “effect,” I have to pause for a second to double-check myself. Their meanings are related, their spellings are similar. Even their pronunciation is nearly the same. But one of them causes something and the other is the result. And knowing the difference is a good thing.
Affect is (usually) a verb. It’s the action, the thing that makes the difference. Something affects someone or something else.
The bright lighting in the theatre affected the actor’s performance. The stricter diet and exercise routine should affect her health in a positive way. The nightmare will probably affect me all day.
Effect is (usually) a noun. It’s the result, the consequence of the action.
The effects of the new law aren’t fully known yet. If you quit smoking, it will have a positive effect on your health. It’s only a matter of time before we all feel the effects of climate change.
Effect is a little more flexible, too, in the way it’s used in phrases. New policies can take effect (not take affect) and once it does, it’s officially in effect. It can be turned into an adjective, too, which can be an effective way to get your point across.
A couple of tricks that might help
If you need a little mnemonic device to help you remember which is which, I’ll share mine with you. I think to myself that “A” is for “action” and “affect.” So if it’s a verb, it’s affect.
Lifehacker Managing Editor Virginia Smith shared another good one with me: She thinks of the phrase “special ef-x,” because special effects are objects. So if the word she’s writing is a thing (noun), it starts with “E.”
You could also use this suggested phrase from Writer’s Digest: “The action is affect, the end result is effect.”
Time to make it harder
Now that you know the rule, you know what comes next: The exceptions! This is why English is so fun.
Affect is almost always a verb, except in the rare moments when it is a noun used to describe a person’s emotion or desire. Reader’s Digest writer Meghan Jones, who has a lovely first name, gives us a great example of this:
“Affect,” as a noun, describes a feeling, emotion, or demeanour, and it will often be preceded by an adjective: “I noticed my friend’s sad affect and asked if he was OK.”
And effect is a noun, except when it’s occasionally a verb that means “to cause something to happen.” Jones has an example of that, too:
“Effect” as a verb means “to bring about,” and you’ll see it almost exclusively used before “change,” as in “Young people have a lot of power to effect change.”
Those cases are less common, though, so if you can mostly remember that affect is the action and effect is the result, you’ll be right most of the time. It will affect your writing, and the effect is that you’ll look smarter.