Affect vs Influence

When to use each in English, with meaning, register, and examples.

 AffectInfluence
Meaningto change or influence somethingTo have an effect on someone or something.
CEFR levelA2B1
Part of speechverbnoun
Usage notesUse 'affect' to describe how one thing changes another. It is not interchangeable with 'effect', which is a result. Avoid using 'affect' as a noun.Used in both formal and informal contexts to describe how one person or thing affects another. Be cautious not to confuse it with 'affect' which is more emotion-based.

Frequently asked questions: Affect vs Influence

What's the difference between "Affect" and "Influence"?

"Affect" means: to change or influence something "Influence" means: To have an effect on someone or something.

When should I use "Affect" and "Influence"?

They can all be used in everyday English.

Are "Affect" and "Influence" the same CEFR level?

"Affect" is at A2, "Influence" is at B1 on the CEFR scale.