comparison
Learn when to use affect or effect in academic, business, and everyday writing.
Use "affect" as a verb most of the time. Use "effect" as a noun most of the time.
In psychology, "affect" can be a noun. "Effect" can be a verb in formal contexts meaning "bring about."
If you can replace the word with "influence," choose affect. If you can replace it with "result," choose effect.
Use this quick matrix to compare core words in this guide and jump directly into deeper lookup pages.
affect
A subjective feeling experienced in response to a thought or other stimulus; mood, emotion, especially as demonstrated in external physical signs.
effect
The result or outcome of a cause.
impact
The striking of one body against another; collision.
influence
The power to affect, control or manipulate something or someone; the ability to change the development of fluctuating things such as conduct, thoughts or decisions.
Example sentences pulled from our lexical corpus to show natural context.
affect
Does the amount of rain affect the growth of crops?
effect
Smoking has an ill effect upon health.
impact
What thought do you think had the biggest impact on the English in the Middle Ages?
influence
Do you think our climate has an influence on our character?
Yes, but it is formal. Most writing should use "cause change.".
Not always. "Impact" can sound vague in analytical writing.