Vocabulary A2–B2 6 min read Updated 9 June 2026

Quick answer: Affect is a verb meaning to influence: The weather affects my mood. Effect is a noun meaning a result: The effect was immediate. Remember: AFFECT = Action (verb); EFFECT = End result (noun).

Comparison Table

WordMeaningExampleCommon Use
affectverb — to influence or change somethingStress affects sleep quality.academic writing, IELTS essays, health topics
effectnoun — a result or outcomeWhat effect did the medicine have?side effects, greenhouse effect, cause and effect

Using Affect (Verb)

Affect is most commonly a verb. It means to have an influence on something or to cause a change. You can test whether affect is correct by replacing it with another verb such as influence or change — if the sentence still makes sense, affect is right.

The cold weather affects crop yields.

Did the news affect your decision?

Lack of sleep can seriously affect your concentration.

The budget cuts will affect every department.

Notice how you can swap in influence: "The cold weather influences crop yields" — it works. That confirms affect is the right choice.

Affected / Affecting

Like any verb, affect has different forms: affects (third-person singular), affected (past tense / past participle), affecting (present participle).

The virus affected thousands of people last year.

The issue is affecting our productivity.

Using Effect (Noun)

Effect is most commonly a noun. It refers to a result, outcome, or impact. You can check by replacing it with the word result — if that works, use effect.

The effect of the new policy was immediate.

What are the long-term effects of stress?

The medication had no visible effect.

Special effects made the film spectacular.

Note that effect can be pluralised: effects. It commonly follows articles and adjectives: the effect, a positive effect, side effects, sound effects.

Common Phrases with Effect

  • in effect (meaning essentially or in practice)
  • take effect (to begin to work)
  • to great effect (successfully)
  • side effect, domino effect, greenhouse effect

The RAVEN Memory Trick

The most popular way to remember the difference is the RAVEN mnemonic:

Remember

Affect is a

Verb,

Effect is a

Noun

Alternatively, use the initial-letter trick: Affect = Action (verb); Effect = End result (noun).

Rare Exceptions

Both words have secondary, less common uses that advanced learners should know:

  • Effect as a verb (formal): to effect a change means to bring a change about entirely. This is much rarer than affect as a verb: The new CEO effected major reforms.
  • Affect as a noun (psychology): in clinical contexts, affect describes a patient's emotional state or mood: The patient showed flat affect. This is technical vocabulary unlikely to appear in everyday writing.

For 99% of everyday and academic writing, simply remember: affect = verb, effect = noun.

Common Mistakes

Mistake 1 — Using effect as the verb

✗ The new law will effect everyone.
✓ The new law will affect everyone.

Mistake 2 — Using affect as the noun

✗ What is the affect of too much sugar?
✓ What is the effect of too much sugar?

Mistake 3 — Forgetting plural forms

✗ The side affects were mild.
✓ The side effects were mild.

Mistake 4 — Mixing both in one sentence

✗ How does stress effect you? The affect can be serious.
✓ How does stress affect you? The effect can be serious.

Affect vs Effect in IELTS and Academic Writing

These words appear constantly in academic and IELTS writing tasks. Getting them right immediately improves your credibility. Here are examples typical of Task 2 essay writing:

Air pollution affects public health in many ways.

The effects of climate change are already visible.

Social media affects the way young people communicate, and its effects can be both positive and negative.

Quick Check: Affect or Effect?

Four questions — choose the correct word for each sentence.

1. “The weather can ___ your mood.”

2. “What is the ___ of stress on the body?”

3. “Pollution ___ the quality of the air.”

4. “The drug had no visible ___.”

Frequently Asked Questions

Is affect a verb or a noun?
Affect is almost always a verb in everyday English. It means to influence or change something: "The rain affected our plans." In psychology, affect can be a noun referring to emotional expression, but this is a technical use most learners will rarely need. For general and academic writing, treat affect as a verb.
Is effect a verb or a noun?
Effect is almost always a noun meaning a result or outcome: "The effect of the medicine was impressive." In formal and legal English, effect can be a verb meaning to bring something about completely: "to effect change." However, this usage is rare and could confuse readers. Unless you are writing very formal documents, use effect as a noun only.
How can I remember the difference between affect and effect?
Use the RAVEN mnemonic: Remember Affect is a Verb, Effect is a Noun. Or the initial-letter trick: AFFECT = Action (verb starting with A), EFFECT = End result (noun starting with E). Another method: try substituting "influence" (for affect) or "result" (for effect) — whichever substitution makes sense tells you which word to use.
Can affect and effect both appear in the same sentence?
Yes, and it is perfectly correct: "How does stress affect you? The effects can be serious." Or more elegantly: "Pollution affects the environment, and its effects are felt globally." When both words appear, affect is doing the verb job and effect is doing the noun job. This can actually be a stylistic tool in academic writing to show you know the distinction.
What are common collocations with effect (noun)?
Common collocations: side effect, greenhouse effect, domino effect, ripple effect, knock-on effect, adverse effect, desired effect, dramatic effect, long-term effect, short-term effect, take effect (= begin to work), come into effect (= become active), in effect (= essentially). Note: you have an effect ON something: "the effect of pollution on health" (not "the effect to health").
What are common collocations with affect (verb)?
Common collocations: adversely affect, directly affect, negatively/positively affect, significantly affect, deeply affect, affect performance, affect health, affect the outcome, affect one's mood. Note: affect is followed by an object (the thing being influenced), not a preposition: "stress affects sleep" (not "stress affects on sleep"). You are "affected by" something: "She was deeply affected by the news."
How do affect and effect appear in IELTS writing?
Both words appear frequently in IELTS Writing Task 2 essays on topics like environment, health, technology, and education. Correct usage demonstrates grammatical accuracy. Typical uses: "Air pollution affects public health." "The effects of climate change are well documented." "Social media affects relationships, and these effects are both positive and negative." Mixing them up is a common error examiners notice.
Is "effected" ever correct?
Yes, but only when effect is used as a formal verb meaning to bring something completely into being: "The board effected major changes." This is rare, formal, and mainly found in legal or business writing. In most contexts, "affected" (past tense of affect the verb) is what you want. If you are unsure, avoid "effected" as a verb — use "brought about" or "achieved" instead to express the same idea.
Do native speakers confuse affect and effect?
Yes, very frequently. "Effect" used as a verb when "affect" is meant is one of the most common errors in published English, social media, and even formal documents. The confusion is so widespread that style guides like the Chicago Manual of Style and Oxford Style Manual both dedicate explicit sections to this pair. Knowing the rule puts you ahead of many native writers.
What is the plural of effect?
The plural of effect is effects: "What are the long-term effects of too much screen time?" Common plural forms in fixed phrases: side effects, special effects, sound effects, after-effects. Note that affect (as a verb) does not have a plural — verbs conjugate rather than pluralise. However, the third-person singular is "affects": "Stress affects everyone differently."