"This affects or effects" refers to the correct use of "affects" as a verb meaning to influence or change something, and "effects" as a noun meaning the result or outcome of a change. Confusing them is a common error in written English.
Use "affects" when describing a change or influence. For example, "The new policy affects employee work hours." Here, "affects" shows that the policy influences how long people work.
Use "effects" when referring to results. For example, "The effects of the policy were seen in reduced overtime." The word "effects" names the outcomes, such as fewer hours worked beyond normal shifts.
"Affects" is always a verb. It describes an action that changes or impacts something else. It follows standard subject-verb agreement: "This affects everyone." "She affects decisions." "They affect performance."
"Effects" is always a noun. It names the result of a change. It can be singular ("the effect") or plural ("the effects"). For example, "The side effects of the medication were severe." "The economic effects of inflation are widespread."
Think of it this way: A cause produces an effect. The cause acts on something, which means it affects it. The outcome is the effect.
The most frequent error is using "effects" as a verb. Saying "The weather effects my mood" is incorrect. The correct form is "The weather affects my mood."
Another mistake is confusing the spelling because both words sound similar. This happens even among native speakers. A useful trick is to substitute "impact" for "affects" and "results" for "effects." If the substitution makes sense, you're likely using the right word.
For example: "The storm affected travel plans" - replacing "affected" with "impacted" works. "The storm had effects on travel" - replacing "effects" with "results" also works. But "The storm impacted travel" cannot be replaced with "The storm effects travel," which sounds wrong.
Consider a study on sleep deprivation: "Lack of sleep affects cognitive function." Here, "affects" shows the influence of poor sleep on thinking ability.
The same study may report: "The effects of sleep loss included slower reaction times and memory lapses." "Effects" names the measurable outcomes.
In a business context: "The merger affected departmental budgets." "The financial effects were felt across all divisions." Again, "affects" describes the influence; "effects" names the consequences.
Although rare, "effect" can be a verb meaning "to bring about" or "to accomplish." This usage is formal and mostly found in legal or technical writing. For example: "The court ordered the effect of the new regulation." This means the regulation was implemented.
But even in this case, "effect" as a verb is not interchangeable with "affect." You cannot say "The regulation affects the process" and mean the same thing as "The regulation effected the process." The meanings differ: one is influence, the other is implementation.
Most everyday writing uses "affects" as a verb and "effects" as a noun. Using "effect" as a verb requires careful attention to context and tone.
Take a clinical trial on a new drug. Researchers observe: "The drug affects blood pressure levels." This shows the drug's influence on a physiological measure.
Later, they report: "The effects included dizziness and nausea in 30% of patients." This lists the side effects experienced.
Using "effects" as a verb here would be incorrect: "The drug effects blood pressure" is not standard English. The correct phrasing remains "affects" for influence and "effects" for results.
| Word | Part of Speech | Meaning | Correct Example |
|---|---|---|---|
| affects | verb | to influence or change | The noise affects concentration. |
| effects | noun | the result or outcome | The effects of stress are visible. |
Many assume "effects" can be used as a verb in casual speech. Phrases like "This effects change" are widespread online and in informal writing but remain incorrect in formal contexts.
Even some style guides treat this confusion as a persistent issue. The Chicago Manual of Style (17th ed.) explicitly states: "Affect is a verb; effect is a noun. Do not use effect as a verb unless in rare technical contexts." Chicago Manual of Style
Similarly, Merriam-Webster confirms: "Affect is usually a verb meaning to influence. Effect is usually a noun meaning a result." Merriam-Webster Dictionary
I once edited a grant proposal where the applicant wrote: "The program effects positive outcomes." This was corrected to "The program affects positive outcomes" - but that still sounded off. The correct version was: "The program affects participants' outcomes" or "The program produced positive effects."
After multiple revisions, the team realized that "effects" was being misused as a verb. Once clarified, the language became accurate and professional.
Use "affects" when describing actions that influence or alter something. It fits in sentences like:
Use "effects" when naming results or outcomes. Examples include:
Never use "effects" as a verb in standard American English. Even in creative writing, doing so risks appearing unprofessional.
When you see "this affects or effects," the correct choice is "affects" if you mean influence. Use "effects" only if you're talking about results.
Remember: "Affects" = verb. "Effects" = noun. One is action. The other is outcome.