Affect vs effect: Learn the difference with examples

The two words effect and affect sound very similar when spoken, but how do you know which one to use when writing?

Learning the difference between affect vs effect can be tricky, but don’t worry; these are some of the most commonly confused words in the English language!

We hope this article helps you to understand the difference. Below you’ll find some general rules and plenty of example sentences so you can work out whether to use ‘affect’ or ‘effect’ in a particular situation.

What’s the difference between affect and effect?

Let’s start with the most basic difference between effect and affect: they are different parts of speech (at least most of the time).

Effect is most often used as a noun

We talk about the effect that something has, or an effect on something.

How do you know if your sentence uses the word as a noun? You can try replacing the word ‘effect’ with ‘consequence’. If the sentence is still correct grammatically, you know you’re dealing with a noun and effect is the correct word choice.

For example, in the sentence: “What affect/effect will this have on our profit this year?”, we could instead say “What consequence will this have on our profit this year?” – and this shows us that we should use the noun ‘effect’.

On the other hand, in the sentence: “How will this affect/effect our profit this year?”, it wouldn’t make sense to say “How will this consequence our profit this year?”, so you know a verb is required.

Here are some more example sentences using effect as a noun:

The effect of global warming is becoming clearer as the years go on.
Do you think our changes have had an effect yet?
Exercising regularly will have a positive effect on your mind and body.

One quick tip for remembering that ‘effect’ is a noun is to think about the effect. ‘The’ is followed by a noun, and the two letter es pair up as a reminder that it’s correct to say ‘the effect’ and not ‘the affect’.

Affect is a verb

Affect is a verb that most commonly means to have an influence on or to cause a change in. For example:

Did the bad weather affect your holiday?
Our company has been badly affected by the recession.
I’m so lucky; I can eat what I like and it doesn’t affect my weight.

In the past, affect was also used as a noun, but nowadays these meanings are more or less obsolete. At least this makes life just a little easier when you’re trying to learn whether to use effect or affect!

Effect can also be used as a verb

The use of effect as a verb is less common than its use as a noun, but it means to bring about or to produce as a result, for example:

It’s expected that these cost-cutting measures will effect great savings.
The president has used his power to effect financial reform in the country.

Is it affect change or effect change?

This is one of the more common structures where effect is used as a verb in English. We’re talking about bringing about change, making it happen, so it is correct to use effect change instead of affect change.

If you’re still having trouble with this, one consolation is that the pronunciation of these two words is almost identical. This means that you don’t need to worry so much about the difference between affect and effect when you’re speaking (unlike advice and advise, which look almost the same but sound a little different.

Using affect vs effect in common phrases

There are some other situations when you may be confused about when to use affect vs effect. Here are some other common phrases in English which always use effect:

Take effect / come into effect / go into effect

Definition: to produce results, begin, or become operative

The new rules come into effect next week.
Your medicine will take effect in about an hour.
When did this law go into effect?

Once the thing in question has taken effect, we say it is in effect. But, this phrase also has another meaning…

In effect

Definition: basically, in fact, in essence

Lisa was convinced that this was the right thing to do, when in effect it was the exact opposite.
The Governor’s latest statement in effect contradicted his previous one.

To good effect

Definition: productively or successfully

The school has used the donated money to good effect.

‘Good’ can be replaced with another adjective such as ‘great’, ‘amazing’, etc.

To/of no effect

Definition: in vain or unsuccessfully

I’ve asked our son a hundred times to tidy his room, but to no effect.
The teacher’s efforts to silence the class were of no effect.

We can also use ‘to little effect’ to mean ‘with little success’.

(Something) to that effect

Definition: having that general meaning; similar to that just mentioned

My grandson works in internet communications, or something to that effect.

Side effect

Definition: a secondary effect, especially an undesired one, for example of medicine

I had to stop taking my medicine because of the side effects it was causing.
If you experience any side effects, especially headaches, please call me immediately.

Special effects

Definition: techniques used in the production of film and television scenes to create an illusion

The special effects really brought that move to life.

Sound effects

Definition: sounds other than music or dialogue that are made artificially to sound like something else for a movie, show, or other broadcast

I wonder how they created the cooking sound effects for that radio show?

Domino/ripple/snowball effect

Definition: A chain of events that occur as the result of one initial event (and, in the case of a ripple and snowball effect, becoming increasingly significant).

I had no idea what a domino effect that one conversation would have!
We’re hoping to see a ripple effect from this marketing campaign.

You can visualize all of these if you imagine the ripples spreading out from an initial impact in water, or a snowball rolling down a hill and gaining speed and volume as it does so. We can also use ‘snowball’ as a verb – and you can read about that in our article on snow idioms and expressions.

That’s about all there is to know about how to use affect vs effect correctly. We hope these examples in sentences have helped, but if you have any others you’re unsure about, feel free to leave a comment below.

Affect vs effect: What’s the difference and how to use them in a sentence?