Yukaもちろんそうするよ — Of course I will! This natural phrase uses two key Japanese words: もちろん (of course) and そうする (to do so). Let's break this phrase down and learn how to use it naturally!
ReiThis is a really useful phrase for agreeing enthusiastically. Once you understand the structure, you can build many similar expressions!
At a Glance
| Part | Meaning | Notes |
|---|---|---|
| もちろん | Of course, certainly, naturally | Adverb — expresses that something is obvious or goes without saying |
| そうする | To do so, to do that | そう (so/that way) + する (to do) |
| よ | Sentence-ending particle | Adds assertion/emphasis in casual speech |
| Full phrase | Of course I will! / Of course I'll do that! | Casual, assertive agreement |
もちろん — Of Course
もちろん (勿論) is a versatile adverb meaning “of course,” “certainly,” or “naturally.” It expresses that something is obvious or goes without saying.
- もちろん！— Of course!
- もちろんいいよ — Of course it's fine!
- もちろん知ってる — Of course I know
- もちろん参加します — I will of course participate
YukaA: 一緒に来る？ Are you coming with me?
B: もちろん！ Of course!
そうする — To Do So / To Do That
そうする combines そう (in that way / like that) + する (to do). It means “to do so” or “to do that” — referring back to something already mentioned or implied.
- そうする — to do so / to do that
- そうしよう — let's do that / I'll do that
- そうしてください — please do so
- そうするつもり — I intend to do that
Reiそうする is highly context-dependent — it refers to something already established in the conversation. もちろんそうするよ = “Of course I'll do that” (referring to something the other person suggested or expected).
Using もちろんそうするよ in Conversation
| Situation | Exchange |
|---|---|
| Friend asks if you'll join | A: 次のパーティー来るよね？ You're coming to the next party, right? / B: もちろんそうするよ！ Of course I will! |
| Parent asks if you'll help | A: 夕飯の後、皿洗いしてね。Wash the dishes after dinner. / B: もちろんそうするよ。Of course I will. |
| Colleague confirms a task | A: 資料は明日までに送ってね。Send the materials by tomorrow. / B: もちろんそうします。Of course I will. |
Related Expressions for Agreement
| Expression | Meaning | Register |
|---|---|---|
| もちろん！ | Of course! | Casual |
| もちろんそうするよ | Of course I will! | Casual |
| もちろんです | Of course (it is) | Polite |
| 当然です (とうぜんです) | Naturally / Of course | Formal |
| もちろんそうします | Of course I will (polite) | Polite |
| ぜひ！ | Absolutely! By all means! | Casual-formal |
Quick Quiz
Fill in the blank:
- A: 宿題やった？B: ___！ → もちろん (Of course!)
- A: 明日早く来てね。B: ___そうします。→ もちろん
- A: 手伝ってくれる？B: ___そうするよ！→ もちろん
More Japanese Lessons
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