The two words are annoyingly similar (although not as similar, the Owl reminds me, as the hoo, hoo, and hoo of his birth language. 😉 )
Let’s look at the separate meanings of the two words, then think about a way to remember which is which.
Affect means that something causes something to change, or to become different in some way.
Eating chocolate always affects Ray’s skin by giving him a rash.
Effect means the change that is wrought.
For Ray, the effect of eating chocolate is that he gets a rash.
Aha! Do you see what I see? Affect is a verb. Effect is a noun.
So one way to check which word should be used is to see what place it has in a sentence. Which part of speech is it?
Eating chocolate always has that _____. Would you put a noun or a verb in that blank? I hope you said noun, because there you’d use effect.
Chocolate _____ Ray’s skin in an uncomfortable way. Noun or verb? You’re right if you said verb and chose affect (well, in this case, to get the tense right, it needs to be affects).
But are there any exceptions? Is it really as simple as that?
Did you see the Grammar Owl shake his feathers in an expression of exasperation with the oddities of the English language? It seems there are always exceptions.
Fortunately, the exceptions don’t occur very often in regular speech or writing.
There is a use of affect in psychology that makes the word into a noun, but you’re not likely to have to use it that way.
There is also a case in which you’d use effect as a verb. This one is more likely to crop up in conversation or writing, particularly in formal situations.
The lunch committee wanted to effect changes to the lunch program that would provide alternatives to chocolate desserts.
In most instances, though, you can use the quick “noun or verb” test to decide which word to use.
I hope all this has had the effect of clarifying this word use for you!
If you would like to affect the question or quandary answered in the next Grammar Owl post, you can ask your question in the comments below, or send an email through the Owl’s contact form.
Thanks for reading!