# Affect vs effect

Canonical: https://duckyhelper.com/learn/grammar/affect-vs-effect/
Updated: 2026-10-01

Most of the time, affect is a verb that means to influence (The rain affected the game), and effect is a noun that means a result (The rain had an effect on the game). Quick test: if you can put a, an or the in front of it, you need effect. Two rarer uses: effect as a verb means to bring about (effect change), and affect as a noun is a psychology word for visible emotion.

## The rule

| Word | Usually | Means | Example |
| --- | --- | --- | --- |
| affect | verb (an action) | to influence or change something | *Lack of sleep can affect your memory.* |
| effect | noun (a thing) | a result | *Lack of sleep has a big effect on memory.* |

> **Tip: Memory trick**
>
> Purdue OWL uses RAVEN: **R**emember, **A**ffect is a **V**erb and **E**ffect is a **N**oun. Another trick: **A**ction is **A**ffect; **E**nd result is **E**ffect.

**Wrong vs right**

| Wrong | Right | Why |
| --- | --- | --- |
| *The new rule had a big affect on attendance.* | *The new rule had a big effect on attendance.* | After *a big*, you need a noun: *effect*. |
| *How did the move effect you?* | *How did the move affect you?* | You need a verb meaning *influence*: *affect*. |
| *The side affects include headaches.* | *The side effects include headaches.* | *Side effects* are results, so the noun. |

## The two rare uses

- **Effect as a verb** means *to bring about* or *to cause to happen*: *The new principal wants to effect several changes.* This is formal and fairly rare.
- **Affect as a noun** is used in psychology for the emotion a person shows: *The patient had a flat affect.* You will rarely need it in school writing.

## Worked examples

**Example 1: the a/an/the test**

Problem: *The medicine had no (affect / effect) on my cough.*

1. Look before the blank: *no*. Can you put *an* there? *The medicine had an ___ on my cough.* Yes.
2. A word that can follow *an* is a noun, so *effect*.

Answer: *The medicine had no effect on my cough.*

**Example 2: swap in influence**

Problem: *Does music (affect / effect) how well you study?*

1. Swap in *influence*: *Does music influence how well you study?* It fits.
2. *Influence* is a verb here, so *affect*.

Answer: *Does music affect how well you study?*

## Common mistakes and fixes

| Mistake | Fix |
| --- | --- |
| Writing *had an affect* | After *a*, *an*, *the*, *any* or *no*, use *effect*. |
| Writing *effected* when you mean *influenced* | *The storm affected our plans.* Use *effected* only for *brought about*. |
| Writing *affect change* | To mean *bring about change*, the phrase is *effect change*. |
| Plural mix-ups | *Special effects*, *side effects* and *sound effects* are all nouns. |

## Practice

**Five affect or effect questions**

1. *Lack of sleep can ___ your memory.*
   A. affect
   B. effect
   C. affects
   D. effects

   Answer: affect. After *can*, you need a base verb meaning *influence*: *affect*. *Effect* would mean *bring about your memory*, which makes no sense, and the *-s* forms do not follow *can*.

2. *The new rule had a big ___ on attendance.*
   A. affect
   B. effect
   C. affected
   D. effected

   Answer: effect. After *a big*, you need a noun meaning *result*: *effect*. The other choices are verb forms, and the noun *affect* is a psychology term that does not fit.

3. *How did moving to a new school ___ you?*
   A. effect
   B. affect
   C. affects
   D. effects

   Answer: affect. After *did*, you need a base verb meaning *influence*: *affect*. *Effect you* would mean *bring you about*, and the *-s* forms do not follow *did*.

4. *The medicine's side ___ include headaches.*
   A. affects
   B. affect's
   C. effect's
   D. effects

   Answer: effects. *Side effects* are results, so you need the plural noun *effects*. *Affects* is a verb form, and the apostrophe forms show ownership, which does not fit.

5. Which word means *bring about* in this sentence? *The new principal wants to ___ several changes, such as a later start time.*
   A. affect
   B. affects
   C. effect
   D. effects

   Answer: effect. When the meaning is *to bring about*, the verb is *effect*. *Affect several changes* would mean influence changes that already exist. The *-s* forms do not follow *to*.

## Frequently asked questions

### Is it affected or effected?

Almost always *affected*, meaning influenced: *The snow affected our trip.* Use *effected* only when you mean *brought about*: *The protests effected a change in the law.* If you can swap in *influenced*, write *affected*.

### Is it impact or effect?

Both can be nouns meaning a result: *a big effect*, *a big impact*. *Impact* also suggests force or a collision. In school writing, *effect* is often the plainer choice, and *affect* is the plainer verb than *impact*.

### Why do so many people mix them up?

They sound almost the same, and both are about change and results. The verb and noun pattern solves most cases: an action is *affect*, a thing is *effect*. The rare uses are worth knowing but seldom needed in school writing.

## Sources

- [Purdue OWL, Spelling: Common Words that Sound Alike](https://owl.purdue.edu/owl/general_writing/grammar/spelling_common_words_that_sound_alike.html), accessed 2026-10-01
- [Purdue OWL, Affect/Effect Exercise](https://owl.purdue.edu/owl_exercises/spelling_exercises/affect_effect/index.html), accessed 2026-10-01

## Related

- [Its vs it's](https://duckyhelper.com/learn/grammar/its-vs-its/)
- [Who vs whom](https://duckyhelper.com/learn/grammar/who-vs-whom/)
- [Verb tense](https://duckyhelper.com/learn/grammar/verb-tense/)
- [Grammar study guides](https://duckyhelper.com/learn/grammar/)

## Try asking Ducky

- "Check every affect and effect in my lab report."
- "Give me ten fill-in-the-blank affect or effect sentences."
- "Explain why this one is effect, using my sentence."

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