Cool MateAll of a sudden vs Instantly vs Rapidly vs Suddenly
When to use each in English, with meaning, register, and examples.
All of a sudden
Top 2,000 (common)
Instantly
Top 5,000 (fairly common)B2adverb
Rapidly
Top 1,000 (very common)B2adverb
Suddenly
Top 1,000 (very common)A2adverb
| All of a sudden | Instantly | Rapidly | Suddenly | |
|---|---|---|---|---|
| Pronunciation | 🇬🇧 //ɔːl əv ə ˈsʌdən//🇺🇸 //ɔl əv ə ˈsʌdən// | 🇬🇧 /["/ˈɪnstəntli/"]/🇺🇸 /["/ˈɪnstəntli/"]/ | 🇬🇧 /["/ˈræpɪdli/"]/🇺🇸 /["/ˈræpɪdli/"]/ | 🇬🇧 /["/ˈsʌdənli/"]/🇺🇸 /["/ˈsʌdənli/"]/ |
| Meaning | Unexpectedly or very quickly. | Right away, without waiting. | quickly or fast | Happening quickly and without warning |
| Example | All of a sudden, it started to rain heavily. | Her voice is instantly recognizable. | to **increase/spread/expand rapidly** | I **suddenly realized** what I had to do. |
| Register | Neutral | Neutral | Neutral | Neutral |
| How common | Top 2,000 (common) | Top 5,000 (fairly common) | Top 1,000 (very common) | Top 1,000 (very common) |
| CEFR level | - | B2 | B2 | A2 |
| Part of speech | adverb | adverb | adverb | |
| Collocations | all of a sudden, a loud noise, all of a sudden, they appeared, all of a sudden, it happened | instantly available, instantly recognizable, instantly regret, instantly noticeable | grow rapidly, change rapidly, develop rapidly, increase rapidly | suddenly appear, suddenly realize, suddenly stop, suddenly change |
| Antonyms | gradually, slowly, over time | gradually, slowly, eventually | slowly | gradually, slowly |
| Common mistakes | Using in overly formal contexts., Confusing with similar phrases like 'suddenly.', Omitting 'of' in the phrase. | Using 'instantly' with past tense incorrectly, e.g., 'I instantly saw' instead of 'I saw instantly'., Confusing it with 'immediately' when the emphasis on speed differs., Forgetting to use it with an action verb. | 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 | Using 'suddenly' with the wrong tense (e.g., 'sudden' for past actions)., Confusing 'suddenly' with 'sudden', forgetting it needs to modify verbs., Using 'suddenly' too often, making writing sound repetitive. |
| Usage notes | Used to describe a change that happens suddenly. Suitable for both spoken and written English; avoid in formal writing. | Use 'instantly' in both spoken and written English to emphasize immediate action. It's appropriate in most contexts but less common in very casual conversations. | Use 'rapidly' in contexts where something is happening very quickly. It's more formal than 'quickly' and might not be suitable for casual conversations. | Use 'suddenly' to describe an unexpected change or event. Commonly used in storytelling or descriptions of surprising moments. Avoid in very formal contexts. |
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Frequently asked questions: All of a sudden vs Instantly vs Rapidly vs Suddenly
What's the difference between All of a sudden, Instantly, Rapidly, and Suddenly?
All of a sudden: Unexpectedly or very quickly. Instantly: Right away, without waiting. Rapidly: quickly or fast Suddenly: Happening quickly and without warning
Can you show an example of each?
All of a sudden: All of a sudden, it started to rain heavily. Instantly: Her voice is instantly recognizable. Rapidly: to **increase/spread/expand rapidly** Suddenly: I **suddenly realized** what I had to do.
Can I use All of a sudden, Instantly, Rapidly, and Suddenly interchangeably?
Not always. All of a sudden, Instantly, Rapidly, and Suddenly 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.