急に (きゅうに): 'Suddenly' / 'All of a Sudden'
What it means
急に describes something happening suddenly, abruptly, or unexpectedly — without warning. As an adverb it sits in front of the verb and tells you how the action happened:
急に雨が降ってきた。
きゅうに あめが ふって きた。
It suddenly started to rain.
急に + verb = the classic pattern.
ヤッタンは急に呼ばれた。
ヤッタンは きゅうに よばれた。
Yattan was suddenly called over.
モチが急に立ち止まった。
モチが きゅうに たちどまった。
Mochi suddenly stopped walking.
Something unexpected, with no lead-up.
The feeling is everyday and natural — it's the word you reach for when ordinary plans get interrupted or the weather turns on you.
How to form it
急に is the adverb form. Its source word is the な-adjective 急(きゅう)な, which means "sudden" or "urgent." That gives you two forms for two jobs:
| You want to modify… | Use | Example |
|---|---|---|
| a verb (an action) | 急に | 急に泣き出した (suddenly burst out crying) |
| a noun (a thing) | 急な | 急な変化 (a sudden change) |
This is the regular な-adjective pattern: な-adjective + に → adverb, な-adjective + な → before a noun. So 静か → 静かに / 静かな works the same way as 急 → 急に / 急な.
More examples
Adverb 急に, modifying a verb:
先生が急に話を止めた。
せんせいが きゅうに はなしを とめた。
The teacher suddenly stopped talking.
弟が急に泣き出した。
おとうとが きゅうに なきだした。
Yattan's little brother suddenly burst into tears.
弟 = Yattan's brother here.
Adjective 急な, before a noun:
急な用事ができました。
きゅうな ようじが できました。
Some urgent business came up.
急な + noun. 用事 = errand / business.
気温の急な変化に気をつけて。
きおんの きゅうな へんかに きを つけて。
Watch out for sudden changes in temperature.
急に vs 突然 (とつぜん)
Both mean "suddenly," and in many sentences they swap freely. The difference is tone: 突然 is more dramatic and a bit more literary — "all of a sudden," out of nowhere — and is common in writing and storytelling (突然、電気が消えた = "all of a sudden the lights went out"). 急に has a more everyday, conversational feel and is the safer default in daily speech. For most ordinary situations, 急に is exactly what you want.
Don't confuse it with 急いで (いそいで)
These look related but mean different things. 急いで ("hurriedly / in a hurry") comes from the verb 急ぐ (いそぐ = "to hurry") and describes doing something fast: 急いで食べた ("I ate in a hurry"). 急に is about something happening unexpectedly, not quickly. 急に出かけた = "I went out suddenly (unplanned)"; 急いで出かけた = "I went out in a hurry (rushing)."
Common mistakes
- Using 急に before a noun. Before a noun you need the adjective form: 急な変化 (✓), not 急に変化. Keep 急に for verbs.
- Using 急な before a verb. Before a verb you need the adverb form: 急に降ってきた (✓), not 急な降ってきた.
- Mixing up 急に and 急いで. 急に = suddenly (unexpected); 急いで = hurriedly (fast). 急いで食べた means you ate quickly, not suddenly.
- Forcing 突然 everywhere. 突然 is fine, but it sounds more dramatic. In casual conversation, 急に is usually the more natural choice.
Quick recap
- 急に = "suddenly / abruptly," an adverb placed before a verb: 急に雨が降ってきた.
- It comes from the な-adjective 急な = "sudden / urgent," used before a noun: 急な変化.
- Rule: 急に + verb, 急な + noun.
- 突然 also means "suddenly" but feels more dramatic; 急いで means "hurriedly" (from 急ぐ) — a different word.
Your turn
Choose 急に or 急な to complete each sentence.
Start the 5-question drill →Frequently asked questions
What's the difference between 急に and 急な?
Same word, two forms. 急に is the adverb — use it before a verb (急に止まった = suddenly stopped). 急な is the な-adjective form — use it before a noun (急な変化 = a sudden change).
Is 急に the same as 突然?
Both mean 'suddenly' and often swap freely. 突然 is more dramatic and literary ('all of a sudden'), while 急に sounds more everyday. In casual speech, 急に is usually the more natural pick.
How is 急に different from 急いで?
急に means 'suddenly / unexpectedly' (from the adjective 急). 急いで means 'hurriedly / in a hurry' (from the verb 急ぐ). 急いで食べた = ate quickly; 急に食べ始めた = suddenly started eating.
Can 急に go before a noun?
No. Before a noun, switch to the adjective form 急な: 急な用事 (urgent business), 急な雨 (a sudden rain). Keep 急に for modifying verbs.