The Farlex Grammar Book > English Spelling and Pronunciation > Common Mistakes and Commonly Confused Words > affect vs. effect
affect vs. effect
What is the difference between affect and effect?
In everyday speech, affect and effect usually share the same pronunciation: /əˈfɛkt/ (although, when articulated carefully, effect is pronounced /ɪˈfɛkt/). They also have similarities in their most common meanings, which can cause many writers to confuse the two terms.
Affect is usually a verb meaning “to act upon or produce a change or effect in,” as in:
- “Be aware that snowy conditions may affect your commute this morning.”
- “I think all this dust is affecting my breathing.”
- “I’ve never seen a film that affected me so deeply before.”
Effect, on the other hand, is a noun meaning “a result produced by some cause or the action of an agent.” For example:
- “The decision to create bike lanes had the unintended effect of slowing down traffic across the city.”
- “Your writing really has a profound effect on me!”
- “That medication has some potent side effects.”
Essentially, effect is the result of affect—that is, if you affect something, you produce an effect.
Other meanings of affect and effect
It’s also important to note that both affect and effect have other meanings, though they are used less commonly.
Affect has a secondary meaning as a verb, which is “to simulate, imitate, make a pretence of, or put on a false appearance,” as in:
- “He always affects a worldly and tolerant demeanor, but, in reality, he’s a very narrow-minded individual.”
Affect can also be a noun meaning “a feeling or emotion, especially as conveyed through facial expression or body language,” as in:
- “I couldn’t help but notice that he had a rather somber affect when I saw him in town earlier.”
(Uniquely, when affect has this meaning as a noun, it is pronounced /ˈæfɛkt/.)
Finally, effect can also function as a verb, meaning “to cause, bring about, or accomplish.” For example:
- “My efforts to effect change in the company’s policies have so far been unsuccessful.”
This secondary meaning of effect is perhaps what gives writers difficulty when trying to remember its spelling, as its meaning (“to cause or bring about”) is similar to the meaning of affect (“to act upon or produce change”). Again, this use of effect refers specifically to producing a result—you effect some kind of outcome, such as change, hope, a cure, a decision, etc., that is stated immediately after the verb. With the verb affect, meanwhile, the result is often vague or implied. For example:
- “The bright lights affected my vision.” (The lights acted upon the speaker’s vision, with the specific outcome being implied, so affect is correct.)
- “The bright lights effected my vision.” (My vision is not an outcome or result, so effect is incorrect.)
- “The group is trying to effect a repeal to the antiquated law.” (A repeal is the result or outcome of the group’s action, so effect is the correct verb.)
- “The group is trying to affect a repeal to the antiquated law.” (The group is probably not trying to act upon or influence a repeal, so affect is incorrect.)
Spelling Tricks and Tips
Just remember that affect refers to acting upon something or someone, while effect refers to the end result.
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