verb

affect

uh-FEHKT

verb

To influence or make a difference to something.

"The weather can affect your mood."

"Lack of sleep can affect your concentration."

To pretend to have or feel a quality; to put on.

"He affected an air of confidence he didn't really feel."

"She affected surprise, even though she already knew the news."

How to Use Affect

Learner’s notes

In plain EnglishTo have an influence on something, or change it in some way.

Common mistake

Affect is usually the VERB (to influence): "the storm affected the harvest." Effect is usually the NOUN (the result): "the storm had an effect on the harvest."

Easily confused with

effect →

Word Forms

affected past tense, affected past tense, affect plural, affected plural, affects plural, affects singular, affect singular, affected singular, affectest singular, affectedst singular, affecteth singular, affects singular

Study it as flashcards or scroll it in Flow — saved to your collection.

Test yourself on “affect” A quick quiz — meaning, synonyms & usage →

Fill the Gap

Can you complete this real example?

The weather can _____ your mood.

Etymology

From Latin afficere, "to act upon, influence."