Affect or Effect?

The Difference between "Affect" and "Effect"

The words "affect" and "effect" are often confused by writers. The confusion is understandable because they sound similar and their meanings are related (e.g., to affect something creates an effect).
The Quick Answer

Affect

(verb) "to change" or "to have an impact on"
  • Their decisions affect your life. correct tick
  • (Their decisions have an impact on your life.)
"Affect" is a verb. Other versions of "affect" are "affects," "affected," and "affecting."

Effect

(noun) "a result"
  • This is the effect I wanted. correct tick
  • (This is the result I wanted.)
"Effect" is a noun. The only other version is the plural "effects."
affect or effect?

Using "Affect"

What Does "Affect" Mean?

In basic terms, "affect" means "to change," but that is too simplistic. It can also mean "to have an impact on" or "to transform.". Here are some examples:
  • Do not use low-fat milk. It will affect the taste. correct tick
  • (It will change the taste.)
  • Did the cold affect you? correct tick
  • (Did the cold have an impact on you?)
  • Mark's experiences in Africa affected his outlook on life. correct tick
  • (Mark's experiences in Africa transformed his outlook on life.)
Put simply, "to affect something" means "to change something."
  • I want to affect the vote. correct tick
  • (This means "I want to change the vote.")
In this example, notice that "affect" is written with "to" in front. This tells us that "affect" is a verb. As it's a verb, the following versions are also possible: "affects," "affecting," "affected," and "affect" (without "to" in front).

Using "Effect"

What Does "Effect" Mean?

In basic terms, "effect" means "a result," but that is also too simplistic. It can also mean "result," "outcome," "consequence," or "appearance." Here are some examples:
  • Your lectures had an immediate positive effect. correct tick
  • (Here, "effect" means result.)
  • The effect of your work is apparent. correct tick
  • ("Effect" means outcome.)
  • Did the reprimand have any effect? correct tick
  • ("Effect" means consequence.)
  • You must be pleased with the effect you've created. correct tick
  • ("Effect" means appearance.)
Put simply, "an effect" means "a result."
  • I want to create an effect the world will remember. correct tick
  • (This means "I want to create a result the world will remember.")
Notice that "effect" is written with "an" in front. This is a key point. "Effect" is usually preceded by an article (i.e., "a," "an," or "the"). This tells us that "effect" is a noun. As it's a noun, the only other possible version is the plural "effects."

Confirmatory Test on Affect and Effect

It's your go. Select the correct one:

Top Tip

  • Use "effect" if the word before is "an" or "the."
This tip works because "effect" is a noun, and only nouns can be preceded by "a," "an," and "the." Verbs can't.

Quick Test on Affect and Effect

It's your go again. Select the correct one:
Get it? Here is a quick test to help you practise this tip:

A Trick To Spot "Effect" and "Affect"

affect or effect?
If you're unsure whether to use a version of "affect" or "effect," replace it with the word "consequence." If your sentence still makes sense, then use "effect." This trick works because "consequence" is a noun, just like "effect." There is no verb version of "consequence." In other words, you cannot say "they consequence," "he consequenced," "she consequences," or "we are consequencing."

Try the Substitution Trick

If the noun "consequence" works in your sentence, use the noun "effect" ("effects" for plural).

Let's try some examples:

Example 1:

  • What effect/affect did the drought have on your business?
Apply the trick: Use "consequence."
  • What consequence did the drought have on your business? correct tick
  • (This sounds okay, so "effect" is correct.)
  • What effect did the drought have on your business? correct tick

Example 2:

  • Did the drought effect/affect your business?
Apply the trick: Use "consequence."
  • Did the drought consequence your business? wrong cross
  • (This sounds wrong, so "effect" is wrong.)
  • Did the drought affect your business? correct tick

Example 3:

  • This incident is effecting/affecting your decision.
Apply the trick: Use "consequence."
  • This incident is consequence your decision. wrong cross
  • (This sounds wrong, so "effect" is wrong.)
  • This incident is affecting your decision. correct tick
  • (Once you know "effect" is wrong, you must then use the correct version of "affect." In this case, "affecting."

It's Not That Simple Unfortunately

Most of this page is dedicated to telling you that "effect" is a noun and "affect" is a verb. That is an appropriate starting point for learning about the difference between "effect" and "affect," but unfortunately it is not always true. Be aware that "effect" can be a verb, and "affect" can be a noun.

The Verb "To Effect"

"To effect" as a verb is fairly rare, but it is useful in business writing. It means "to bring into being." For example:
  • We will effect the new law on Monday. correct tick
  • The new policy will be effected as soon as the paper is signed. correct tick

The Noun "Affect"

The noun "affect" is extremely rare. It is used in psychology to describe a subjective feeling caused by a thought or other stimulus. It is similar to mood or emotion and carries a connotation of there being external physical signs. For example:
  • The patient displayed an unusual affect when questioned. correct tick

A Video Summary

Here is a short video summarizing the difference between "affect" and "effect." video lesson

Are you a visual learner? Do you prefer video to text? Here is a list of all our grammar videos.

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This page was written by Craig Shrives.