Skip to main content

Define Effect vs. Affect: Grammar Guide

Robin is an educator and works in online publishing. Her mission is to remove apostrophes in address labels.

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.

Examples of Effect in Common Usage

  • 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.)

Examples of Affect in Common Usage

  • 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.

Examples of Effect as a Verb

  • 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.)

Examples of Affect as a Noun

  • 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

Take a Quiz

Test yourself!

Sources and Further Reading

Thoughts, Comments or Questions

Miss Duke on April 05, 2014:

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

Elizabeth Parker from Las Vegas, NV on August 21, 2013:

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

Kyle on April 29, 2012:

"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.

Karl on October 14, 2011:

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 :)

Nicolas Connault on February 14, 2010:

@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.

Nicolas Connault on February 14, 2010:

Here's an ambiguous case:

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

Suzanne on September 25, 2009:


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!


Donna Dove on March 18, 2009:

Data is BOTH singular AND plural.

Carolyn Augustine from Iowa on April 28, 2008:

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.

Anjuli on April 03, 2008:

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

KJG on November 29, 2007:

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 from Downingtown on August 01, 2007:

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 Edmondson (author) from San Francisco on April 16, 2007:

Thanks, Mark. I appreciate the feedback. ;)

Mark Rollins on April 16, 2007:

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

Robin Edmondson (author) from San Francisco on April 11, 2007:

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.

Kristy on April 11, 2007:

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


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?

EGetts on April 06, 2007:

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 from Birmingham, Michigan on February 11, 2007:

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

Robin Edmondson (author) from San Francisco on November 28, 2006:

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

Thanks for the idea! ;)

Nicole on November 27, 2006:

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

Robin Edmondson (author) from San Francisco on November 14, 2006:

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 from Birmingham, Michigan on November 14, 2006:

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 Edmondson (author) from San Francisco on November 13, 2006:

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

wajay_47 on November 12, 2006:

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