affect vs effect
Affect is almost always a verb meaning to influence something. Effect is almost always a noun meaning the result. If you can put 'the' in front of it, you want effect; if it's the action being done, you want affect.
The difference
- affect (verb) — to influence or make a difference to something
- effect (noun) — a result or consequence
- effect (verb (formal)) — to bring about, as in 'effect change'
Examples
- The delay did not affect the outcome.
- The delay had no effect on the outcome.
How to remember
A is for Action (affect = verb); E is for End result (effect = noun).
The common trap
Writing 'the affect' — if there's a 'the', you almost certainly need effect.
Affect or effect: the reliable grammar test
Start with the standard rule: affect is the action of influencing, while effect is the result of that influence. In 'The delay affected sales', affected is the action. In 'The delay had an effect on sales', effect is the thing the delay produced.
Two less common uses explain most apparent exceptions. To effect something is a formal verb meaning to bring it about, as in 'effect a change'. Affect can be a noun in psychology meaning an observable emotional expression. In ordinary workplace writing, the standard verb-and-noun rule solves almost every case.
A quick sentence test helps. If the gap follows the, an or another determiner and names a result, choose effect. If a subject is doing something to an object, choose affect. Then check whether the formal phrase 'bring about' fits; if it does, effect may be the verb.
Forms and examples
- affect: usual verb: influence
- Budget changes may affect recruitment.
- effect: usual noun: result
- The change had little effect on recruitment.
- effect: formal verb: bring about
- The new director hopes to effect a lasting change.
- affect: specialist noun: observable emotional expression
- The clinician described a flat affect.
Quick test
The revised deadline did not ___ the final decision.
Check the answer
affect. The blank is a verb meaning influence.
The revised deadline had no ___ on the final decision.
Check the answer
effect. The blank is a noun naming the result, and it follows no.
The committee wants to ___ a change in policy.
Check the answer
effect. Here the formal verb means bring about.
Related word distinctions
- practise vs practice: In UK English, practise is the verb and practice is the noun.
- stationary vs stationery: Stationary (with an a) means not moving; stationery (with an e) is writing materials.
Sources checked
These distinctions are exactly what Word Meaning and Contextual Word Choice questions test. Read the Word Meaning guide or Contextual Word Choice guide, then practise the drill.