Meaning & Usage
The Japanese grammar pattern ついでに (tsuide ni) is used when you perform a secondary action because it's convenient to do so while already engaged in, or about to engage in, a primary action. It suggests efficiency, like "killing two birds with one stone," or making the most of a situation. Essentially, it means, "Since I'm doing A, I might as well do B." The key is that the primary action (A) creates an easy and convenient opportunity for the secondary action (B).
This pattern conveys a sense of opportunism or incidental action. Your main purpose is the first action, and the second is something extra you can easily fit in. For instance, if you're already headed to the station (primary action), you might pick up groceries on the way because the supermarket is nearby (secondary action). Getting groceries isn't why you left the house, but it's convenient to do it then.
ついでに has a casual and practical nuance, frequently appearing in daily conversation. It implies a natural progression from one task to another due to proximity, timing, or shared effort. While generally suitable for everyday use, including business conversations among colleagues, or even with superiors in appropriate contexts (e.g., "駅へ行くついでに、この書類も出してきてください。" - "While you're going to the station, please drop off these documents too."), avoid it in highly formal or academic writing. Its English equivalents include "while I'm at it," "on the way," "taking the opportunity to," or "since I'm doing X, I'll also do Y."
Imagine you're on a path to complete task A. Task B happens to be on, or very close to, that path. This makes it efficient to complete both without much extra effort or deviation. The first action naturally sets the stage for the second.
Structure & Formation
The grammar pattern ついでに connects to verbs and nouns. The form of the preceding word indicates the primary action or situation that creates the opportunity for the secondary action.
Verb + ついでに
Verbs can be used in their plain (dictionary) form, past (た-form), or ている-form.
| Verb Form | Connection | Example |
|---|---|---|
| Dictionary Form | 書く + ついでに | 手紙を書くついでに |
| た-Form (Past) | 買った + ついでに | 本を買ったついでに |
| ている-Form | 掃除している + ついでに | 部屋を掃除しているついでに |
Noun + の + ついでに
When connecting to a noun, the particle の is inserted between the noun and ついでに.
| Noun | Connection | Example |
|---|---|---|
| 買い物 | 買い物 + の + ついでに | 買い物のついでに |
| 散歩 | 散歩 + の + ついでに | 散歩のついでに |
Adjectives (い-adjectives and な-adjectives) do not directly connect to ついでに. If you need to express an adjective-related opportunity, you would typically rephrase it using a noun or verb.
Example Sentences
Daily Chores & Errands
散歩のついでに、ポストに手紙を出した。
Sanpo no tsuide ni, posuto ni tegami o dashita.
While I was out for a walk, I dropped the letter in the postbox.
駅へ行くついでに、コンビニで雑誌を買ってきた。
Eki e iku tsuide ni, konbini de zasshi o katte kita.
While I was going to the station, I bought a magazine at the convenience store.
洗濯するついでに、このタオルも洗っておいて。
Sentaku suru tsuide ni, kono taoru mo aratte oite.
While you're doing the laundry, please wash this towel too.
東京に出張するついでに、友達に会おうと思っている。
Tōkyō ni shutchō suru tsuide ni, tomodachi ni aō to omotte iru.
While I'm on a business trip to Tokyo, I'm thinking of meeting a friend.
買い物のついでに、銀行に寄った。
Kaimono no tsuide ni, ginkō ni yotta.
While I was shopping, I stopped by the bank.
Helping Others & Collaboration
郵便局に行くついでに、この荷物も送ってくれますか。
Yūbinkyoku ni iku tsuide ni, kono nimotsu mo okutte kuremasu ka?
While you're going to the post office, could you send this package for me?
会議に出るついでに、資料をコピーしておいた。
Kaigi ni deru tsuide ni, shiryō o kopī shite oita.
While I was attending the meeting, I made copies of the documents.
部屋を掃除しているついでに、窓も拭いておこう。
Heya o sōji shite iru tsuide ni, mado mo fuite okō.
While I'm cleaning the room, I'll wipe the windows too.
ご飯を作るついでに、お味噌汁も作りましょうか。
Gohan o tsukuru tsuide ni, omisoshiru mo tsukurimashō ka?
While I'm making dinner, shall I make miso soup too?
Opportunity & Convenience
旅行のついでに、有名な観光地にも寄ってみた。
Ryokō no tsuide ni, yūmei na kankōchi ni mo yotte mita.
While I was traveling, I also visited some famous tourist spots.
会社に寄ったついでに、資料を取ってきた。
Kaisha ni yotta tsuide ni, shiryō o totte kita.
While I stopped by the company, I picked up the documents.
郵便局へ行ったついでに、切手を買いました。
Yūbinkyoku e itta tsuide ni, kitte o kaimashita.
While I went to the post office, I bought stamps.
図書館に本を返すついでに、新しい本も借りてきた。
Toshokan ni hon o kaesu tsuide ni, atarashii hon mo karite kita.
While returning books to the library, I also borrowed new ones.
大阪へ旅行するついでに、京都にも立ち寄りたい。
Ōsaka e ryokō suru tsuide ni, Kyōto ni mo tachiyoritai.
While traveling to Osaka, I'd like to stop by Kyoto as well.
引っ越しのついでに、要らないものを捨てた。
Hikkoshi no tsuide ni, iranai mono o suteta.
While moving, I threw away unnecessary things.
Common Mistakes
Mistake 1: Confusing Main and Secondary Actions
A common mistake is using ついでに when the "secondary" action is actually the primary purpose, or when both actions are equally important. Remember, ついでに specifically implies that one action is merely an opportunistic addition to another main action.
❌ 公園で遊ぶついでに、犬の散歩をした。
✅ 犬の散歩のついでに、公園で少し遊んだ。
Explanation: If your main goal was to play in the park and you just happened to walk your dog there, the first sentence is confusing. Typically, walking the dog is the primary reason for going to the park. The correct sentence places the dog walk as the primary action, with playing in the park as the secondary, opportunistic action.
Mistake 2: Using for Unrelated or Separate Actions
ついでに implies a logical connection or geographical/temporal proximity between the two actions. It shouldn't be used for two completely separate or unrelated tasks.
❌ 料理をするついでに、本を読んだ。
✅ 料理をする間に、本を読んだ。
Explanation: Cooking and reading are usually not performed in a way that one provides an "opportunity" for the other in the ついでに sense. While you might read while cooking, it's not like cooking makes reading easier or more efficient. ～間に (while/during) or ～ながら (while doing) would be more appropriate.
Mistake 3: Incorrect Verb/Noun Connection
Remember to use the correct forms: plain form verbs (dictionary, た-form, ている form) and Noun + の + ついでに.
❌ 会社ついでに、郵便局へ行った。
✅ 会社のついでに、郵便局へ行った。
Explanation: When connecting ついでに to a noun like 会社 (company), the particle の is essential. This implies "on the occasion of going to/being at the company."
Mistake 4: Overuse in Formal Contexts
While generally flexible, avoid using ついでに in extremely formal speeches, reports, or academic papers where a more precise and less colloquial phrasing might be preferred.
❌ 社長へのご報告のついでに、来週の会議の件もお伝えしました。
✅ 社長へのご報告の際に、来週の会議の件もお伝えしました。
Explanation: While the nuance is similar, ～際に is a more formal and neutral expression for "at the time of" or "on the occasion of," making it more suitable for formal business communications. ついでに can sound a bit too casual when referring to formal duties.
Cultural Notes
The concept of ついでに reflects a strong cultural value in Japan: efficiency and making the most of one's time and effort. People commonly integrate multiple tasks into a single outing or activity to save time, transportation costs, or energy. This approach is highly appreciated, especially when it involves helping others.
For example, it's very natural for a Japanese person to ask a family member or colleague, "駅へ行くついでに、これをポストに出してくれない？" (While you're going to the station, could you drop this in the mailbox?). They expect that the primary trip to the station makes the secondary task of posting a letter a minor, easily accomplished addition. The other person would typically agree, as it's seen as a small favor that doesn't significantly inconvenience them.
This usage also highlights a consideration for others. If you notice someone is already doing something, offering to combine tasks with ついでに can be a thoughtful gesture. It shows you've acknowledged their primary action and are simply taking advantage of the natural flow to assist them or yourself without creating extra work. This emphasis on practicality and mutual convenience is an ingrained part of daily life and communication.
Related Grammar Points
- Wakeda: That's Why, No Wonder, It Means That (Grammar N3)
- Uchi ni: While / Before It Changes (Grammar N3)
- Nuki de (ぬきで) — Without, Leaving Out (Grammar N3)
- It's Been Decided/Scheduled: ことになっている (Grammar N3)
- Not Necessarily (Grammar N3)
- っぽい — -Ish, -Like (Grammar N3)
JLPT Tips
For the JLPT N3 exam, truly understanding ついでに means recognizing its core function: expressing a secondary, opportunistic action performed alongside a primary one. When you encounter ついでに in reading comprehension or grammar questions, always identify which action is primary and which is the additional, secondary task.
Pay close attention to the context. If the two actions appear equally important, or if the "secondary" action seems to be the main purpose, ついでに is likely not the right choice. Instead, look for scenarios where the initial action naturally makes the second one easier or more efficient to complete. For instance, if someone is already headed to a specific place, running a small errand along the way is a perfect use of ついでに.
Also, remember the connection rules: use plain form verbs (including the た-form and ～ている-form) and Noun + の + ついでに. An い-adjective or な-adjective directly preceding ついでに is generally incorrect. Finally, focus on distinguishing ついでに from similar grammar points like ～ながら and ～がてら. The crucial difference lies in ついでに's emphasis on a convenient opportunity arising from the primary action, rather than just simultaneous execution or a dual purpose planned from the start.