Meaning and Usage
"急速" (きゅうそく) means "rapid" or "fast" and is often used to describe something that changes or progresses quickly, such as technology, weather, or conditions. It is a formal adverb or noun and commonly appears in written and spoken Japanese at a neutral or slightly formal level.
Common Collocations
- 急速な進歩 (きゅうそくなしんぽ): rapid progress
- 急速に悪化する (きゅうそくにあっかする): to deteriorate rapidly
- 急速に変わる (きゅうそくにかわる): to change rapidly
These collocations highlight how "急速" is used to emphasize speed in changes or developments.
Usage Notes
"急速" is often paired with verbs or nouns related to change or movement. It is more formal than simply saying "速い" (fast) and is suitable for news reports, academic contexts, or serious conversations. Avoid using it for casual speed descriptions like running fast; instead, use "速い" or "早い".
Common Mistake
Learners sometimes confuse "急速" with "急に" (suddenly). "急速" emphasizes the speed or rapidity of a process, while "急に" focuses on the suddenness of an event. For example, "急速に進む" means "to progress rapidly," whereas "急に進む" means "to progress suddenly."