Cool MateAll of a sudden vs Rapidly
When to use each in English, with meaning, register, and examples.
All of a sudden
Top 2,000 (common)
Rapidly
Top 1,000 (very common)B2adverb
Most common: Rapidly
| All of a sudden | Rapidly | |
|---|---|---|
| Pronunciation | 🇬🇧 //ɔːl əv ə ˈsʌdən//🇺🇸 //ɔl əv ə ˈsʌdən// | 🇬🇧 /["/ˈræpɪdli/"]/🇺🇸 /["/ˈræpɪdli/"]/ |
| Meaning | Unexpectedly or very quickly. | quickly or fast |
| Example | All of a sudden, it started to rain heavily. | to **increase/spread/expand rapidly** |
| Register | Neutral | Neutral |
| How common | Top 2,000 (common) | Top 1,000 (very common) |
| CEFR level | - | B2 |
| Part of speech | adverb | |
| Collocations | all of a sudden, a loud noise, all of a sudden, they appeared, all of a sudden, it happened | grow rapidly, change rapidly, develop rapidly, increase rapidly |
| Antonyms | gradually, slowly, over time | slowly |
| Common mistakes | Using in overly formal contexts., Confusing with similar phrases like 'suddenly.', Omitting 'of' in the phrase. | Using 'rapidly' as an adjective instead of an adverb, Confusing 'rapidly' with 'quickly' in formal writing contexts, Overusing 'rapidly' in informal conversations where simpler words are better |
| Usage notes | Used to describe a change that happens suddenly. Suitable for both spoken and written English; avoid in formal writing. | Use 'rapidly' in contexts where something is happening very quickly. It's more formal than 'quickly' and might not be suitable for casual conversations. |
See it in real clips
Frequently asked questions: All of a sudden vs Rapidly
What's the difference between All of a sudden and Rapidly?
All of a sudden: Unexpectedly or very quickly. Rapidly: quickly or fast
Which is more common: All of a sudden and Rapidly?
Rapidly is the most common in everyday English.
Can you show an example of each?
All of a sudden: All of a sudden, it started to rain heavily. Rapidly: to **increase/spread/expand rapidly**
Can I use All of a sudden and Rapidly interchangeably?
Not always. All of a sudden and Rapidly are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.