Affect vs effect: use the two-second test, and know the two exceptions

The rule: affect is a verb, effect is a noun

Cambridge Dictionary defines the pair in one line each: affect is a verb meaning "influence or cause someone or something to change", and effect is a noun that means "the result of an influence". In its second grammar page, Cambridge adds that you should use the noun effect to talk about the change, reaction or result caused by something.

Walden University's writing help says that the words affect and effect are often confused with one another, and that these are the two most common uses, with exceptions because both words have other meanings.

One sentence shows both words working together: The new rule will affect everyone; the effect will be felt next month. The verb affect describes the action. The noun effect names the result.

The two-second test

Do not try to remember the grammar. Run these tests on the word you want to write.

1. Can you replace it with "influence"? (Noise will influence my sleep.) Then use affect.
2. Can you replace it with "result"? (Noise has a bad result on my sleep.) Then use effect.
3. Is there "a", "an", "the", "this", "any", "no" or an adjective before it? (a bad effect, the effects, no effect) Then it is a noun, so use effect.
4. Is there a subject doing something to an object? (The cold affected the crops.) Then use the verb affect.

A popular memory aid is the word RAVEN: Remember, Affect is a Verb; Effect is a Noun. It is only a memory trick, not a rule of grammar, and it does not cover the two exceptions below, but it works for most sentences.

Apply the test:

• "The weather will ___ our plans." influence fits, so affect.
• "The medicine had no ___." no result fits, and no comes before it, so effect.
• "How does stress ___ your health?" influence fits, so affect.
• "What is the ___ of stress on health?" the comes before it, so effect.

Affect as a verb: examples

Affect (verb) means to change or influence someone or something. It is followed by an object: you affect something or someone.

• Cambridge's example: The accident affected my family emotionally and financially. (Not effected.)
• Stress can affect your sleep.
• The new tax will affect small businesses.
• The weather affects how I feel.
• Does coffee affect your concentration?
• BriefCatch's example: will your legal brief positively affect the outcome of your client's litigation?

The past form is affected. The related adjective is affected too, with a different meaning: an affected accent means a fake or unnatural one.

Affect can also mean to pretend (She affected surprise), but this is rare and formal. You will meet it in books more than in speech.

Common phrases:

• be affected by: Many people were affected by the flood.
• deeply / badly / seriously affected: The region was badly affected.
• affect the outcome, affect the result, affect your health.

If someone or something is doing the changing, you almost always need affect.

Effect as a noun: examples

Effect (noun) names the change, reaction or result. Because it is a noun, it often appears with a, an, the, any, no or an adjective, and it can be plural.

• Cambridge's example: most people these days understand the serious effects of smoking.
• Global warming is one of the effects of pollution.
• There are several factors that have an effect on language learning.
• BriefCatch's example: the threatened litigation had detrimental effects on my client.
• A Walden example: one effect of the earthquake was that many people lost their homes.

Common patterns with the noun:

• have an effect on: The news had an effect on prices.
• side effect: The medicine has a side effect.
• special effects: The film has amazing special effects.
• the effect of X on Y: the effect of sleep on memory.
• in effect (in reality): In effect, the plan is a failure.
• take effect / come into effect / go into effect: The new law comes into effect on Monday.

That last group answers a common search: "Does a law go into effect or affect?" It is go into effect (or take effect). Effect is a noun there. You cannot "go into affect".

The adjective is effective (producing the wanted result) and the adverb is effectively.

The two exceptions: effect as a verb, affect as a noun

Both words have a rarer second job, and this is why the simple rule sometimes seems to fail.

1. Effect as a verb: to bring about, to create. BriefCatch notes that effect is also sometimes used as a verb meaning "create". Its example: the new partner hopes to effect changes in the firm's compensation structure. Here effect means make happen.

• The company wants to effect a change in culture. (to bring it about)
• The new law will effect major reforms.

Test: can you replace it with bring about? Then it is the verb effect. This use is formal and common in business, law and politics. Compare: to affect a change would mean to influence a change that already exists, while to effect a change means to make the change happen.

2. Affect as a noun: visible emotion. BriefCatch also says that affect is sometimes used as a noun meaning "a change in demeanor or mood": the therapist noted a sudden shift in the CEO's affect. This is mainly a psychology and medical term. You will rarely need it in everyday English.

In the noun case, the stress changes: AF-fect (stress on the first syllable) for the psychology noun, but af-FECT for the ordinary verb.

These exceptions are rare. In everyday English, use affect as a verb and effect as a noun, and you will be right in nearly all cases.

How to say affect and effect

The two words sound almost the same, which is why the spelling is so often mixed up.

• affect (verb): uh-FEKT, with a weak first syllable (the schwa) and stress on the second syllable.
• effect: ih-FEKT (or ee-FEKT in careful speech), with stress on the second syllable.

In fast speech, the first syllable of both words is so short that they sound close to "-fekt". The first vowel in effect is slightly closer to "ih", and in affect closer to "uh", but in a sentence it is easy to miss.

So you cannot rely on listening. Rely on the grammar: after a / an / the or an adjective, it is effect. After a subject like it, this or they, it is usually the verb affect.

Practise saying the pairs aloud with the stress on the second syllable:

• "It will af-FECT my plans." / "It will have an ef-FECT on my plans."
• "How did it af-FECT you?" / "What was the ef-FECT?"

Our guide to the schwa sound explains why the first syllable is so weak in words like these, and word stress in English shows how the stress pattern works.

Affected or effected? And other common mistakes

"Are you affected or effected by something?" For the normal meaning (changed or influenced), it is affected: I was affected by the news. Effected means brought about: The manager effected several changes. Cambridge's wrong example shows the common error: The accident effected my family emotionally and financially should use affected.

More mistakes:

• Wrong: How does it effect you? Right: How does it affect you? (verb: influence)
• Wrong: The affect of the new law was big. Right: The effect of the new law was big. (noun: result)
• Wrong: There are several factors that have an affect on learning. Right: There are several factors that have an effect on learning. (Cambridge's example)
• Wrong: Global warming is one of the affects of pollution. Right: ...one of the effects of pollution. (Cambridge's example)
• Wrong: The law goes into affect on Monday. Right: The law goes into effect on Monday.
• Wrong: It had a big effect me. Right: It had a big effect on me. (the noun needs on)

When unsure, rewrite the sentence with the simpler verb influence: The news influenced me. If this works, write affect. If you can say result, write effect.

A final pattern: after the verb have, you almost always need the noun: have an effect on, have no effect, have a big effect. After will or can with no article, you need the verb: will affect, can affect.

Quiz: affect or effect?

Choose the right word. Answers follow.

1. Lack of sleep can ___ your memory.
2. The medicine had no ___.
3. How will the change ___ our team?
4. The ___ of the storm lasted for weeks.
5. The new law will come into ___ in January.
6. Does stress ___ your health?
7. One side ___ is tiredness.
8. The manager hopes to ___ real change.

Answers: 1. affect. 2. effect. 3. affect. 4. effects (plural) or effect. 5. effect. 6. affect. 7. effect. 8. effect (verb: bring about).

Say each completed sentence aloud, stressing the second syllable of the word you chose. Then write two sentences of your own with each word. If you want a partner for this kind of practice, our guide to English speaking practice explains a daily routine, and an AI tutor can notice small grammar slips as you talk.