Meaning and Usage
"反応" (はんのう) primarily means "reaction" or "response." It is used to describe how someone or something reacts to a stimulus, event, or situation. This can be physical, emotional, or verbal.
Common Contexts
You will often see "反応" used in everyday conversation when talking about people's reactions to jokes, questions, or news. It is also common in medical or scientific contexts to describe bodily or chemical reactions.
Collocations and Patterns
- 反応を示す (はんのうをしめす): to show a reaction; used when someone visibly or verbally reacts.
- 反応が早い/遅い (はんのうがはやい/おそい): quick/slow reaction; describes the speed of response.
- 反応を観察する (はんのうをかんさつする): to observe a reaction; often used in medical or experimental settings.
Register and Nuance
"反応" is a neutral noun suitable for both formal and informal contexts. It is often used in scientific, medical, and everyday conversational Japanese.
Common Mistake
Learners sometimes confuse "反応" with "応答" (おうとう), which also means "response" but is more specific to answering or replying, especially in communication contexts like phone calls or messages. Use "反応" when emphasizing the reaction aspect rather than just a reply.