Define Effect vs. Affect: Grammar Guide

Updated on October 24, 2014
Affect or Effect? A Helpful Flowchart.
Affect or Effect? A Helpful Flowchart.

Common Usage of Affect and Effect

First, let's talk about the ways these commonly confused words most often appear. If you follow these simple rules, you'll be correct in 99% of situations involving the words "affect" and "effect." After we get the common usage figured out, I will go over the exceptions so you can feel confident about that final 1% of usage

  • Effect is almost always a noun. It means "result" or "consequence" and usually refers to the influence a subject has on an object, such as The effect of heat on various metals. It is often preceded by the words a, an, any, the, take, into, and no. (These words may be separated from effect by an adjective.)
  • Affect is almost always a verb. It means "to influence" and "to produce a change" such as Alcohol drastically affects decision making. Less commonly, it can also mean "to pretend to feel" or "to assume a behavior" as in, She affected an Australian accent for the role. As a verb, it can be preceded by a subject or an adverb.


  • What was the effect of taking the drugs on the runner? (What was the result of taking the drugs?)
  • Her statement had an emotional effect on the teachers. (Here, effect is preceded by "an," separated by an adjective.)


  • Will the campaign contributions affect his voting? (Will the contributions influence his voting?)
  • Rainy weather always badly affects my arthritis. (Rainy weather always produces a change in my arthritis. Notice that affect is preceded by the adverb "badly.")
  • I affected interest in his speech, but my mind was wandering. (I pretended to feel interest in his speech.)

The Basics: Common Usage of Affect and Effect

Type of Speech:
to influence something
a result or consequence
Additional Meaning:
to pretend to feel or have
scenery e.g. "special effects"

Affect and Effect: The Exceptions to the Rule

Now, what about the 1% of the time when affect is a noun and effect is a verb? Luckily, this only occurs in very specific circumstances. I'll define each situation right now.

  • Effect is only used when you need to say "to bring about" or "to cause to happen." However, usually in these cases your sentence will run smoother with a different verb, since effect as a verb isn't common in most vernacular.
  • Affect as a noun appears in an even more specific circumstance: it's used to describe a person's emotional appearance or behavior in psychiatric terms.


  • Her statement effected great emotion with the teachers. (Her statement caused great emotion.)
  • The family dialogue effected a positive atmosphere. (The family dialogue brought about a positive atmosphere.)


  • Her affect was greatly subdued when she made her decision. (Her emotional expression was subdued.)
  • The patient shows a manic affect and appears psychologically unstable. (The patient is displaying manic emotional behavior and appears unstable.)

The Exceptions: Uncommon Usage of Affect and Effect

Type of Speech
psychological behavior
to bring about; to cause

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      • profile image

        Miss Duke 3 years ago

        Great hub! I finally learned the difference! It left me baffled for quite a while in before times or whenever I had to do my essays and then this would come up. Thank you so much!

        ~Miss Duke

      • epbooks profile image

        Elizabeth Parker 4 years ago from Las Vegas, NV

        Common mistake that is so many make. Very helpful hub!

      • profile image

        Kyle 5 years ago

        "I will affect human thought eternally, effecting life forever."

        I will take verbosity over confusing the masses any day.

        Cause and effect teaching MUST be replaced with reason.

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        Karl 6 years ago

        This was very helpful. I've mixed these two words up so many times over the years. Now I might just be able to remember which is which. Thanks :)

      • profile image

        Nicolas Connault 8 years ago

        @Suzanne, the answer is "affect". You would only use "effect" if it meant "bring about". In your sentence, "bring about" doesn't make sense:

        "Technology & performance will directly bring about your facility operations".

        However, the following sentence can be ambiguous:

        "A rise in consumer satisfaction will directly [affect|effect] the increase in sale prices".

        The question here is one of causation vs influence. "Affect" means influence, while "effect" means causation.

      • profile image

        Nicolas Connault 8 years ago

        Here's an ambiguous case:

        "The [affect|effect] I saw on his face was astounding!"

      • profile image

        Suzanne 8 years ago


        In the following sentence, would affect or effect be correct "Technology & performance will directly xffect your facility operations". I am in a bit of a grammar war with a co-worker, and I really need an independent party to solve this for us!


      • profile image

        Donna Dove 9 years ago

        Data is BOTH singular AND plural.

      • wannabwestern profile image

        Carolyn Augustine 9 years ago from The Land of Tractors

        This is my number one usage peeve. I don't know why! It just seems so ill-informed to misuse these ones! I like the useful information in your hubs. Thanks.

      • profile image

        Anjuli 9 years ago

        What ___(affect/effect)does the administration have on our economy.

      • profile image

        KJG 10 years ago

        Some resource/reference books acknowledge the use of data as both a singular and a plural noun using either a singular or plural verb. Data is technically plural and datum technically is singular.

        Just a note........

      • jacksonBusiness profile image

        jacksonBusiness 10 years ago from Downingtown

        Hi how are you, Your words are enlightening. When you get a chance check out some of my work, and let me know.

        Keep Hubbin


      • Robin profile image

        Robin Edmondson 10 years ago from San Francisco

        Thanks, Mark. I appreciate the feedback. ;)

      • Mark Rollins profile image

        Mark Rollins 10 years ago

        I had a student as me this question the other day. I wish my answer would have been as good as yours.

      • Robin profile image

        Robin Edmondson 10 years ago from San Francisco

        Yikes, Kristy. You caught a typo mistake, thanks!!! Here's another way of stating from the Lynch Guide to Grammar:

        Affect with an a is usually a verb; effect with an e is (usually) a noun. When you affect something, you have an effect on it. The usual adjective is effective, which means "having the right effect," or "getting the job done" — an effective medicine, for instance. (It can also mean "in effect," as in "the new policy is effective immediately.")

        If the usuals leave you curious, here's the rest of the story: affective as an adjective means "relating to or arousing an emotional reaction"; effect as a verb means "to bring about" or "to accomplish," as in "to effect a change." There's also the noun affect, usually used in psychology, meaning "an emotion" or "feeling.

      • profile image

        Kristy 10 years ago

        This would be very helpful except that it contradicts itself. Affect can be a noun. Affect is never a noun. Which is it?

        First by saying, "Use affect when you mean: TO INFLUENCE SOMETHING RATHER THAN CAUSE or AS A NOUN TO EXPRESS EMOTION"

        Then by saying, "Note: Affect is never a noun and is usually a verb; effect can be either a noun or verb."

        So...can affect be a noun or not?

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        EGetts 10 years ago

        So in the sentence "Inflation has an effect on the buying power of the dollar?" (a rewording of the example sentence given under the affect definitions above) I should use effect (since it is a noun), even though in this case it means "influence" which is a closer in meaning to affect as a verb? But since the noun form of affect doesn't mean influence, then effect is the correct word in this sentence.

      • Ralph Deeds profile image

        Ralph Deeds 11 years ago from Birmingham, Michigan

        A very common mistake. I see it occasionally even in the NY Times.

      • Robin profile image

        Robin Edmondson 11 years ago from San Francisco

        Hi, Nicole. I wrote a hub on raise vs. rise. Here's the url:

        Thanks for the idea! ;)

      • profile image

        Nicole 11 years ago

        Great page! How about a similar one on usage of raise vs. rise? My students have trouble with that one too...

      • Robin profile image

        Robin Edmondson 11 years ago from San Francisco

        I hear it all of the time too; but yesterday I heard someone on KPFA, a local listener sponsored radio station, use it correctly, he said, "The data are in our favor." The singular form of data is datum, which we hardly ever hear. Thanks, Ralph!

      • Ralph Deeds profile image

        Ralph Deeds 11 years ago from Birmingham, Michigan

        How about the growing use of singular verbs with the plural "data?" I was taught to say, e.g., the data are clear. But more often than not I read and hear the data IS clear. Now, use of plural verbs with "data" almost sounds stilted. ????

      • Robin profile image

        Robin Edmondson 11 years ago from San Francisco

        You are always such a great cheerleader, Wajay! Thanks so much! ;)

      • profile image

        wajay_47 11 years ago

        Robin, these hubs are great! Please keep steering us in the right direction. Thanks