Common mistakes
Affect or effect: choosing the right word in a sentence
A delayed train can affect a meeting. The effect may be that the meeting starts late. The two words look similar, but one usually names an action and the other usually names what happens because of that action.
Choose affect or effect by identifying whether the sentence needs an action or a result, and recognize the less common formal uses.
Read and practice
Read the examples and try the written questions in this guide. Listening recordings are not available for this lesson yet.
Try the written questions
affect / effect /əˈfekt/ / ɪˈfekt/
The short answer
Use affect as a verb for influencing something. Use effect as a noun for the result of an influence or action.
The new timetable affected our journey, and its effect was a longer wait at the station.
Why it works: Affected tells what the timetable did. Effect names the result it produced.
5 more examples
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The construction work affected traffic on the main road.
Affect is a verb here. The construction work influenced the traffic.
Not this:The construction work had
an effect on trafficon the main road. What changes: Effect is a noun here. The phrase names the result that the construction work produced. -
Lack of sleep can affect your concentration.
The sentence needs a verb for the influence that lack of sleep has.
Not this:
One effectof lack of sleep is poor concentration. What changes: Effect names one result of not sleeping enough. -
The medicine did not affect her appetite.
Affect describes whether the medicine changed her appetite.
Not this:The medicine had
no effect onher appetite. What changes: Effect is the noun after no and before the phrase on her appetite. -
The teacher's feedback affected how I planned the next draft.
Feedback influenced the writer's planning, so the verb affect fits.
Not this:
The effect of the feedbackwas a clearer plan for the next draft. What changes: The noun effect identifies the result of the feedback. -
The policy may affect the price of a monthly pass.
The policy may influence the price, so the sentence needs the verb affect.
Not this:
A possible effectof the policy is a higher price for a monthly pass. What changes: Effect names the possible outcome of the policy.
Read the full guide
Ask two questions before you choose. Does the sentence need an action, as in influence? Choose affect. Does it need a thing that happened as a result? Choose effect. Then read the sentence again to check that the grammar fits.
Find the action and the result
Use affect when one thing influences another. Use effect when you are naming what follows from that influence. A storm affects a match. A postponed match is an effect of the storm.
Verb: The storm affected the match. Noun: The effect of the storm was a postponed match.
Use affect as the usual verb
Affect usually has an object after it: affect a plan, affect a person, or affect a decision. It does not mean cause in every case. It can mean influence only partly. A price rise may affect what a family buys without deciding every purchase.
The late delivery affected the schedule for the afternoon.
Use effect as the usual noun
Effect often appears with an article, a quantity, or a preposition: an effect, a strong effect, the effect of, and an effect on. These shapes can help you see that the sentence needs a noun.
The announcement had a calming effect on the group.
Notice the less common formal uses
In formal writing, effect can be a verb meaning bring about: The agreement effected a change in the rules. This is not the usual word for everyday conversation. In psychology and medicine, affect can be a noun for a person's visible emotional expression. Keep the common meanings in mind unless your subject needs these technical senses.
The committee hoped to effect a change in the timetable.
Check your sentence before you send it
You want to say that a noisy room made it harder for you to study. Which word fits: The noisy room ___ my studying?
Use affected. The room influenced your studying, so the sentence needs a verb. You could also write: The noisy room had an effect on my studying.
Before you go
Remember this
In ordinary English, affect is usually the verb for influence: noise affects concentration. Effect is usually the noun for a result: noise has an effect on concentration. Check whether your sentence needs an action or a result, then use the common pattern.
Practice with the written examples
You can practice with the written questions in the Learn tab. Each answer includes an explanation.
Try the written questionsListening test not available yet
This lesson does not have the recordings needed for a listening test. Use the written questions in the guide to check your understanding.
Try the written questionsQuestions about "Affect or effect: choosing the right word in a sentence"
What is the main difference between affect and effect?
Affect is usually a verb meaning influence. Effect is usually a noun meaning a result or change. For example, a delay can affect a journey, and a longer journey can be an effect of the delay.
The construction work affected traffic on the main road.
How can I tell whether to use affect or effect?
Ask whether the sentence needs an action or a result. Use affect for the action of influencing something. Use effect when you are naming the consequence, often in phrases such as the effect of or an effect on.
The construction work had an effect on traffic on the main road.
Can effect be a verb?
Yes. In formal writing, effect can mean bring about or cause, as in effect a change. In most everyday sentences, affect is the verb you need when you mean influence.
Lack of sleep can affect your concentration.
Can affect be a noun?
Yes, but mainly in specialist fields such as psychology and medicine, where affect can mean an observed emotional expression. In everyday English, affect is usually the verb meaning influence.
One effect of lack of sleep is poor concentration.
How do you pronounce affect and effect?
Both words are usually stressed on the second syllable. In careful speech, affect begins with an unstressed uh sound and effect begins with a short i sound, but the sentence meaning is the best guide to the spelling.
The medicine did not affect her appetite.
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