Affect vs. Effect: Know the Difference (with tricks and examples)

Deciding whether “affect” or “effect” is the best choice in a sentence is challenging. The words are spelled similarly and derived from terms that are no longer used. Moreover, “affect” and “effect” sound similar when spoken aloud. The distinction is complicated by regional accents. 

Here, we simplify the “affect” vs. “effect” dilemma by:

• Explaining the differences between their meanings
• Providing examples of their proper uses
• Suggesting strategies for selecting the proper term
• Offering alternative word choices to increase clarity

“Affect” and how to use it

"Affect" is a verb that means “to influence” or “to cause a change to an existing condition.”

“Affect” is best used to describe a change in a quality or quantity. For example:

• Pollution negatively affects air quality.
• Pollution negatively affects the amount of corn harvested.

“Effect” and how to use it 

In contrast to “affect”, the noun “effect” refers to an outcome.

“Effect” is best used to introduce a result. For example: 

• An effect of pollution is a reduced corn harvest.

In this example, “effect” is a subject noun; an effect (reduced harvest) is linked to a condition (pollution). 

• Air pollution exerts a negative effect on the corn harvest.

In the second example, “effect” is an object noun; a condition (pollution) causes the effect (reduced harvest). 

Tricks to remember the difference between “affect” and “effect”

Memorization tricks can help distinguish the uses of “affect” and “effect.” 

The RAVEN method

RAVEN is an acronym for Remember that Affect is a Verb and Effect is a Noun. 

In addition, A = action, which is a verb that represents “affect”; E = end, which is a noun that represents “effect.” 

Of course, to use these tricks, a writer needs a clear understanding of noun and verb functions.

Contextual clues 

Verbs can often be recognized by their familiar conjugated forms.

For example, “affect” can be conjugated into “affects” (present tense, singular) “affected” (past tense), and “is affecting” (present participle). Therefore, when deciding between using “affect” and “effect” in a full sentence, if an -ed/-ing ending sounds right, then the root word “affect” is correct. Moreover, “affect” is not accompanied by an article, such as “an” or “the.”

In another strategy, when “affect” (“affected”/“affecting”) is replaced with “alter” (“altered”/“altering”) and the intended meaning is unchanged, then “affect” (not “effect”) is likely the correct choice: “High electricity use is affecting the power grid.”

In contrast, “effect” cannot be conjugated and takes only two forms: plural (“effects”) and singular (“effect”). Similar to other nouns, “effects” may be preceded by “the”; “effect” may be preceded by “the” or “an.”

With the replacement strategy, if changing “an/the effect” to “an/the (outcome)” or replacing “exerts an effect” with “exerts/causes (an outcome)” does not change the meaning, then “effect” (not “affect”) is probably the correct choice: “An effect of demand is reduced price” and “demand exerts a downward effect on price.” 

Using familiar clues in similar sentences

In the sentences “her confidence was positively affected by the teacher’s encouragement” and “the teacher’s encouragement led to a positive effect by increasing the student’s confidence,” the contextual clues are the -ed ending on “affect” and the article “a” before “negative effect.”

In these examples, an adverb (positively) helps clarify the direction of the change (“affect”), and an adjective (positive) helps clarify the type of “effect.” These modifiers offer additional contextual clues. They also indicate that a sentence may be clarified by avoiding the terms “effect” and “affect” altogether!

Alternative words for “affect” that increase clarity

When modifying terms are not used, the direction of a change indicated by “affect” may be unclear.

Does the statement “the medication affects blood pressure” indicate that blood pressure is decreased or increased? In this case, replacing “affects” with “decreases” provides more information. 

Common single verb pairs that add specificity include:

• increase/decrease, 
• strengthen/weaken, 
• expand/contract, 
• accelerate/decelerate, 
• maximize/minimize, 
• enhance/diminish, 
• lengthen/shorten, and 
• raise/lower. 

Replacing “affect” with a more precise verb may lead to better understanding. 

Using “effect” or not 

Because it describes a result, “effect” is often unnecessary: Why not just describe the result itself? With reference to “effect,” Struck and White (1979) admonished, “The writer who has a definitive meaning to express will not take refuge in such vagueness.” 

Notably, “effect” can be removed without changing the meaning of the first set of examples:

• The corn harvest was reduced by pollution.
• Pollution reduced the corn harvest.

Therefore, removing “effect” is a useful edit, especially when the word count is limited, such as in an abstract.

Considering its vagueness, “the effect” or “the effects” may be best used for attention-attracting titles/headings or in broad statements, such as summaries:

• “The effect of advertising on purchase satisfaction”; 
• “The data show clear effects of long-term exposure to high altitude on weight loss”; and
• “For a better understanding of the effects of student isolation on mental health, longitudinal studies are needed.”

Exceptions to the rules

In English, exceptions are to be expected, and in specific circumstances, “affect” is a noun, and “effect” is a verb.

Specifically, in the psychology context, “affect” is a noun that refers to the outward manifestation of an emotional state: “She presented with a flat affect characterized by few facial expressions.”

Similarly, “effect” can be used as a verb to indicate the creation of a condition (not a change to an existing condition). For example:

• To effect a positive outcome, he ensured that the instrument was properly calibrated.

Final thoughts

In summary, a writer does not need to be a grammarian to use “affect” and “effect” properly. Relying on memorization tricks and contextual clues, an author can confidently select the proper term. 

Having a paper edited by AJE ensures that the correct form is used every time!

Reference

Strunk, Jr., W. and E. B. White. (1979). The elements of style, 3rd ed. New York: MacMillian Publishing Co., Ltd.