Affect vs. Effect: The Difference and How to Remember It

Use affect as a verb meaning "to influence" and effect as a noun meaning "a result." The weather affects your mood; the weather has an effect on your mood. That rule covers almost every sentence you'll write, and the two exceptions below are rare enough that you can learn them in a minute.

The basic rule

Most of the time, the choice comes down to the job the word is doing in the sentence.

A quick way to check: if you can put the, an or an adjective in front of the word, you need a noun, so write effect. "A strong effect," "the side effects," "no effect at all." If the word is the action, with a subject doing it, you need a verb, so write affect. "The delay affected everyone."

Here are a few more pairs that show the switch:

• The new schedule affects three teams. / The new schedule had an effect on three teams.
• Did the medicine affect your sleep? / Did the medicine have any effect on your sleep?
• Rising rents affected small shops first. / The effects of rising rents hit small shops first.

Notice that the meaning barely changes in each pair. Only the grammar changes, and the grammar decides the spelling.

A memory trick that actually works

The trick most teachers use is RAVEN:

Remember, Affect is a Verb, Effect is a Noun.

Another one: affect comes first in the alphabet, and an action (affect) comes before its end result (effect). First you affect something; then you see the effect.

If you'd rather test the sentence than memorize a word, try swapping in "influence" (a verb) or "impact" (a noun):

• "The noise influenced my focus" sounds right, so it's affected.
• "The noise had a bad impact on my focus" works, so it's a noun slot and the word is effect.

Exception 1: effect as a verb

Effect can be a verb, but it means something different: to bring about or to cause to happen. You'll see it mostly in formal, business and political writing.

• The new principal effected real change in a single year. (She made change happen.)
• Protesters hoped to effect a shift in policy.

Compare the two verbs side by side:

• The manager affected the schedule. (She changed or disrupted a schedule that already existed.)
• The manager effected the schedule. (She created it and put it into place.)

Because the verb effect almost always appears with words like "change," "reform," "a transition" or "a cure," a good rule of thumb is this: if the object is "change," pause and ask whether you mean caused change (effect) or influenced change (affect). In most everyday sentences, you mean the first: "effect change."

Exception 2: affect as a noun

In psychology and medicine, affect is a noun that means the visible expression of emotion: facial expression, tone of voice, body language. It's pronounced with the stress on the first syllable, AF-fect.

• The patient spoke in a monotone and showed a flat affect.
• Her affect brightened when the conversation turned to her children.

Unless you're writing for a psychology class or a clinical setting, you can safely forget this one. It won't come up in an email, an essay about history or a report at work.

One more meaning: affect as "to pretend"

There's a second, older sense of the verb affect: to put on a manner or attitude that isn't natural. This is where the adjective affected (meaning artificial or showy) comes from.

• He affected a British accent after one semester in London.
• Her affected laugh made the meeting awkward.

It's still a verb, so RAVEN still points you to the right spelling.

Fixed phrases to memorize

Some expressions always use effect because the word is a noun inside them. These are the ones that trip people up most:

• take effect: The rule takes effect in January.
• in effect: The ban is still in effect.
• side effect: Drowsiness is a common side effect.
• to that effect: She said something to that effect.
• for effect: He paused for effect.
• cause and effect: an essay on cause and effect

And the related adjective effective (producing results) is always spelled with an e. "Affected," on the other hand, is the past tense of the verb: "Who was affected by the outage?"

Quick quiz: affect or effect?

Try these before you look at the answers.

1. The cold weather didn't ___ our plans.
2. What ___ will the new law have on renters?
3. Caffeine ___s people in different ways.
4. The changes will take ___ next week.
5. The new CEO wants to ___ a complete turnaround.
6. Her tone was calm, but her ___ seemed anxious to the therapist.
7. Students were badly ___ed by the strike.
8. The special ___s in the film were impressive.

Answers:

1. affect: a verb after "didn't."
2. effect: a noun after "what" ("what result").
3. affects: a verb with the subject "caffeine."
4. effect: the fixed phrase "take effect."
5. effect: a verb meaning "bring about" a turnaround.
6. affect: the psychology noun for emotional expression.
7. affected: past tense of the verb, "influenced."
8. effects: a noun, "special effects."

If you got number 5 or 6 wrong, don't worry. Those are the exceptions, and they're rare in everyday writing.

How to catch the mistake in your own writing

Affect and effect are hard to catch on a reread because both are real words, so a basic spellchecker won't flag them. A few habits help:

• Search your draft for "affect" and "effect" and check each one against RAVEN. It takes a minute.
• Read the sentence with "influence" or "impact" in place of the word and see which one fits.
• Watch the fixed phrases. "Take affect" and "in affect" are the errors editors fix most.

A grammar checker that understands context can also flag these. ZeroTell's Grammar Checker looks for common confusions such as affect/effect and gives a short reason for every change, so you learn the rule instead of just accepting a fix. If a sentence still feels clumsy after you correct the word, the Sentence Rewriter can show you a few other ways to phrase it.

Grammar CheckerFix grammar and phrasing

For more grammar help, see our guide to comma rules and our explanation of who vs. whom, another pair that trips up careful writers.

Key takeaways

• Affect is usually a verb: to influence.
• Effect is usually a noun: a result.
• Effect as a verb means to bring about ("effect change").
• Affect as a noun is a psychology term for visible emotion.
• Phrases like take effect, in effect and side effect always use effect.