【JLPT N4】〜ことになる for Natural Conversation

〜ことになる (~koto ni naru)

Are you studying for the JLPT N3 or N2? Have you encountered the phrase 「〜ことになる」 (~koto ni naru) and felt a slight confusion about its exact meaning? You’re not alone! This structure is absolutely crucial for sounding natural in Japanese, as it allows you to convey actions, results, and decisions without taking personal responsibility for them.

If you feel like your Japanese often sounds too direct, or if you struggle to talk about schedules, organizational decisions, or the unavoidable results of a situation, then mastering 「〜ことになる」 is your next big step. It’s a marker of truly intermediate and advanced Japanese proficiency.

In this comprehensive guide—written specifically for serious JLPT candidates—we will break down 「〜ことになる」, compare it to its confusing cousin 「〜ことにする」, and give you the tools and confidence to use it perfectly every time. Get ready to elevate your Japanese!

Before diving into the grammar detail, here is the JLPT N4 complete guide: 
The Ultimate JLPT N4 Complete Guide: Your Gateway to Working and Living in Japan

Understanding the Core Function of 「〜ことになる」

At its heart, 「〜ことになる」 translates roughly to: “It has been decided that…”, “It turns out that…”, or “It is scheduled to be…”.

The key insight here is the use of the verb なる (naru), which means “to become” or “to turn into.” When combined with こと (koto), which nominalizes the preceding clause, we are essentially saying that the situation described has become a settled fact, a decision, or an established rule.

Crucially, 「〜ことになる」 inherently removes the speaker’s direct involvement or personal will from the decision-making process. The decision is made by someone else, by a group, or by the natural flow of events. This is why it is so often used in professional settings or when discussing rules and external obligations.

How to Connect It (接続 – Setsuzoku)

The connection rules are straightforward. You attach 「〜ことになる」 to the plain (dictionary) form of the verb, or the negative plain form.

• Positive Verb: 食べる (taberu) + ことになる → 食べることになる
• Negative Verb: 食べない (tabenai) + ことになる → 食べないことになる
• I-Adjective: A less common but possible usage involves adjectives, often combined with なる directly. (e.g., 忙しくなる / isogashiku naru – but not typically via the structure 〜ことになる unless defining a rule about qualities.)
• Noun/Na-Adjective: Must use だ/である or its variants before ことになる. (e.g., 会長になることになる – kaichou ni naru koto ni naru – It has been decided that he will become chairman.)

Note on Tense: The tense is determined by the final part, 「なる」 (present/future) or 「なった」 (past).

• Present/Future: 転勤することになる (tenkin suru koto ni naru – I will be transferred.)
• Past: 転勤することになった (tenkin suru koto ni natta – I was transferred/It was decided that I would be transferred.)

The Three Main Contexts for Using 「〜ことになる」

To truly master this grammar point for the JLPT, you need to recognize the three distinct situations where it is applied. Though the core meaning of “external decision/result” remains, the context gives it slightly different flavors.

Context 1: Official Decisions, Rules, and Obligations

This is perhaps the most common usage. It is used when an event, rule, or action is decided by a third party (a company, a school, the government, a committee) or by established rules, and the speaker is merely reporting the outcome. The speaker is the recipient of the decision, not the maker of it.

This usage is crucial in professional and academic environments because it politely distances the speaker from the decision, making the statement objective.

Context 2: Schedules and Plans (External Arrangements)

When you are talking about appointments, meetings, or travel plans that have been set by others (like your boss, the travel agent, or another organization), you use 「〜ことになる」. This emphasizes that the schedule is fixed and generally unchangeable by the speaker.

Context 3: The Result or Outcome of a Situation (Natural Consequence)

Sometimes, 「〜ことになる」 is used to describe a result or conclusion that naturally follows from a series of events or facts, even if no formal “decision” was made. It’s used to state what the facts implicitly conclude.

Everyday Examples for Context and Practice

Let’s look at three practical examples that cover these different contexts. Pay close attention to the nuance provided by 「〜ことになる」 compared to a simple dictionary form verb.

Example Set A: Official Decision/Obligation

Imagine you work for a large company. You don’t decide where you work; your management does.

Example 1: Job Transfer

「来月から大阪支社へ転勤することになりました。」

(Raigetsu kara Ōsaka shisha e tenkin suru koto ni narimashita.)

Translation: It has been decided that I will be transferred to the Osaka branch starting next month.

Analysis: The speaker is simply announcing the management’s decision. They didn’t choose to transfer; they were informed that the transfer is happening.

Example 2: Company Rule

「この会議室では、携帯電話の電源を切ることになっています。」

(Kono kaigishitsu de wa, keitai denwa no dengen o kiru koto ni natte imasu.)

Translation: It is a rule/custom that mobile phones must be turned off in this conference room.

Analysis: By using 〜ことになっている (the ongoing state of the rule), you emphasize that this is an established, non-negotiable rule or policy set by the organization. You are reporting the rule, not making it.

Example 3: External Requirement

「外国人登録証の更新のため、区役所に行かなければならないことになりました。」

(Gaikokujin tōrokushō no kōshin no tame, kuyakusho ni ikanakereba naranai koto ni narimashita.)

Translation: It turns out that I have to go to the ward office to renew my Alien Registration Card.

Analysis: This blends obligation (〜なければならない) with the result (ことになる). The need to go to the office is a legal/administrative necessity that the speaker discovered or was informed of.

Example Set B: Schedule and Arrangement

These examples focus on fixed timings and plans that result from coordination with others.

Example 4: Appointment Setting

「来週の火曜日の午後3時に、クライアントと打ち合わせをすることになりました。」

(Raishū no kayōbi no gogo sanji ni, kuraianto to uchiawase o suru koto ni narimashita.)

Translation: An arrangement has been made to have a meeting with the client at 3 PM next Tuesday.

Analysis: The schedule (the 3 PM meeting) is fixed. It’s an arrangement resulting from communication (e.g., emails back and forth), not a unilateral decision by the speaker.

Example 5: Major Life Event (Fixed Date)

「彼女とは、来年の春に結婚することになりました。」

(Kanojo to wa, rainen no haru ni kekkon suru koto ni narimashita.)

Translation: We have decided (as a couple/family) to get married next spring.

Analysis: While marriage involves personal will, when announcing the date, using 〜ことになる is standard. It elevates the decision from a mere thought to a finalized, announced plan or agreement.

Example Set C: Natural Result or Conclusion

This category involves situations where the outcome is unavoidable given the circumstances, or when a truth has been revealed.

Example 6: Unavoidable Result

「雪で電車が止まってしまい、結局、タクシーで帰ることになりました。」

(Yuki de densha ga tomatte shimai, kekkyoku, takushī de kaeru koto ni narimashita.)

Translation: Because the train stopped due to the snow, in the end, I ended up having to go home by taxi.

Analysis: The situation (train stopping) forced the result (taking a taxi). The speaker didn’t ideally choose the taxi; it was the necessary conclusion of the problem.

Example 7: Discovery or Confirmation

「調査の結果、その情報が完全に間違っていることが分かりました。」 (Note: Often interchangeable with simply 〜ということが分かる)

(Chōsa no kekka, sono jōhō ga kanzen ni machigatte iru koto ga wakarimashita.)

Translation: As a result of the investigation, it was confirmed that the information was completely wrong.

Analysis: This usage reports a fact or truth revealed by evidence. It is a conclusion drawn from the investigation, not an opinion.

The Critical Distinction: 「〜ことにする」 vs. 「〜ことになる」

For JLPT students, the biggest hurdle is almost always differentiating between 「〜ことになる」 and its counterpart, 「〜ことにする」. If you mix these up, you fundamentally change the meaning of your sentence—from reporting a rule to stating a personal choice.

「〜ことにする」 (Koto ni suru) – Personal Decision

The verb する (suru) means “to do.” When combined with こと, you are performing the act of deciding. This structure is used to express the speaker’s own voluntary decision, choice, or attempt to change a habit.

Core meaning: “I decided to…” / “I made it a rule to…” (for myself).

• Focus: The speaker’s will and conscious effort.
• Examples:
  • 「明日からは、毎日30分ジョギングすることにした。」 (I decided to jog for 30 minutes every day starting tomorrow.)
  • 「健康のため、お酒を飲まないことにしている。」 (I have made it a habit/rule for myself not to drink alcohol for the sake of my health.)

Direct Comparison Table

Let’s use a single scenario to see how the meaning shifts dramatically based on the final verb:

Sentence Structure	Meaning	Who Made the Decision?
会議を中止することにした。	I decided to cancel the meeting.	Me (the speaker). It was my choice/will.
会議が中止することになった。	It was decided (by others) that the meeting would be cancelled / The meeting ended up being cancelled.	A third party, the rule, or the situation.
一人で旅行に行くことにした。	I decided to go traveling alone.	Me (the speaker). My personal plan.
一人で旅行に行くことになった。	It was arranged / It turned out that I would go traveling alone.	External factors (e.g., my friend cancelled, so now I must go alone).

Advanced Nuance: Why Distance Matters in Japanese

Understanding the speaker’s distance from the action is central to mastering 「〜ことになる」.

In Japanese culture and business etiquette, explicitly stating “I decided” (〜ことにした) can sometimes sound arrogant or overly self-important, especially when discussing plans that affect others or when reporting decisions made higher up the chain of command.

By using 「〜ことになる」, you are being humble and diplomatic. You are presenting the plan as an unavoidable reality or an external regulation, making the listener feel less criticized or challenged by your “decision.” This is a significant cultural factor in its frequent use.

Addressing Common Mistakes and Pitfalls

Even after understanding the core rule, students often stumble when applying 「〜ことになる」 in complex sentences or when combining it with specific verb types.

Mistake 1: Confusing Naru with Suru in Passive Situations

When reporting a result imposed on you, always use 「〜になる」. Students sometimes mistakenly use the structure for their own passive actions.

• Incorrect: 上司に言われて、残業することにした。 (I decided to work overtime because my boss told me.) — *This implies you chose to obey, which isn’t the primary meaning.*
• Correct: 上司に言われて、残業することになった。 (It was decided/I ended up working overtime because my boss told me.) — *This accurately reports the external obligation.*

Mistake 2: Overusing It for Simple Future Plans

If you are simply stating a personal, flexible future plan, a standard future tense or the structure 「〜つもりだ」 or 「〜予定だ」 is usually sufficient and more natural.

• Simple Plan (Better without 「〜ことになる」): 私は明日、図書館に行く予定です。 (I plan to go to the library tomorrow.)
• Fixed Arrangement (Use 「〜ことになる」): 私は明日、図書館で山田先生と面会することになっています。 (I have a fixed arrangement to meet Professor Yamada at the library tomorrow.)

Mistake 3: The Use of 〜ている (Te-Iru Form)

When 「〜ことになる」 is put into the continuous form 「〜ことになっている」, it exclusively refers to a current, established rule, custom, or ongoing formal arrangement.

〜ことになった: A decision was made (past, finished action).

〜ことになっている: A decision/rule is currently in effect (present state).

Example:

• 「来週は出張に行くことになった。」 (The decision was made last week that I will go on a business trip next week.)
• 「この会社では、制服を着ることになっている。」 (It is a current rule that we wear uniforms at this company.)

Deep Dive: Professional and Formal Usage of 「〜ことになる」

In business Japanese (Keigo), this structure is indispensable. It serves as a tool for formal communication and decision reporting.

Usage in Meetings and Summaries

When concluding discussions, 「〜ことになる」 is used to summarize the consensus reached by the group, avoiding the direct attribution of the decision to any single person.

「皆様の意見を考慮した結果、プロジェクトの締め切りを来月末に延長することになりました。」

(Minasama no iken o kōryo shita kekka, purojekuto no shimekiri o raigetsu matsu ni enchō suru koto ni narimashita.)

Translation: As a result of considering everyone’s opinions, it has been decided to extend the project deadline to the end of next month.

Impact: This phrasing is collaborative and formal, emphasizing the group agreement.

Reporting Unavoidable Situations (Apolgies and Excuses)

In scenarios requiring an apology or explanation for an unavoidable change, 「〜ことになる」 softens the impact by showing the event was externally driven.

「大変恐縮ですが、急なトラブルで、本日中にオフィスに戻らなければならないことになりました。」

(Taihen kyōshuku desu ga, kyū na toraburu de, honjitsu-chū ni ofisu ni modoranakereba naranai koto ni narimashita.)

Translation: I am terribly sorry, but due to a sudden issue, I ended up having to return to the office today.

Impact: The speaker reports the necessity (must return) as a result of the external factor (the trouble), rather than stating a personal wish to leave.

Practice Drill: Test Your Understanding

To ensure you’ve absorbed this lesson for your JLPT prep, choose the most appropriate structure (〜ことにした or 〜ことになった) for the context provided:

Practice Questions

Q1: The company announced its new policy on working hours.

来年から、勤務時間が午前9時から午後5時までに変更（　　　　）。

A)することにした　B)することになった

Q2: You personally decided to stop eating sweets.

ダイエットのために、甘いものをやめる（　　　　）。

A)ことにした　B)ことになった

Q3: You discovered that the meeting venue was suddenly changed.

連絡によると、会議の場所が3階に変更（　　　　）。

A)することにした　B)ことになった

Q4: The manager finalized the budget for the quarter.

今期の予算は、私が一人で決める（　　　　）。

A)ことにした　B)ことになった

Answers and Explanations

A1: B)することになった (The company made the rule; it’s an external decision.)

A2: A)ことにした (The speaker made the choice; it’s a personal decision for dieting.)

A3: B)ことになった (Someone else changed the location; you are reporting the external result.)

A4: B)ことになった (The manager was assigned the duty or ended up having to decide alone, implying the burden or necessity, which is an external condition.)

(Note on A4: If the manager said this to express their own choice, A would be possible, but in a standard reporting context, B highlights the assigned responsibility.)

Beyond the JLPT: Expanding Your Usage

To truly reach fluency, consider how 「〜ことになる」 combines with other grammatical patterns to express complex ideas.

Combining with Potential Form

When used with the potential form (〜できる), it emphasizes that the ability or possibility is the result of external arrangements or rules.

「このシステムのおかげで、自宅からでも仕事ができることになりました。」

(Kono shisutemu no okage de, jitaku kara demo shigoto ga dekiru koto ni narimashita.)

Translation: Thanks to this system, it has become possible for me to work even from home.

Nuance: The possibility is a result of the company implementing the system (external factor), not the speaker suddenly acquiring a new skill.

Combining with Negative Obligation

Used often to express that an obligation has been lifted or that something is no longer necessary due to a change in circumstances.

「天候が回復したので、今日、出発を延期しなくて済むことになりました。」

(Tenkō ga kaifuku shita node, kyō, shuppatsu o enki shinakute sumu koto ni narimashita.)

Translation: Since the weather improved, it turns out that we no longer have to postpone the departure today.

Nuance: The lifting of the necessity (しなくて済む) is the result (ことになった) of the weather improvement (external cause).

Conclusion: Integrating 「〜ことになる」 into Your Daily Japanese

If you’ve made it this far, congratulations! You have mastered one of the most structurally versatile and culturally significant grammar points in intermediate Japanese. 「〜ことになる」 is more than just a phrase; it’s a key component for speaking naturally, formally, and diplomatically.

To solidify your understanding for the JLPT, focus on the following takeaways:

1. External Force: Always remember that the decision, result, or rule originates outside the speaker.
2. Rule vs. Choice: Never confuse 「〜ことになる」 (External Rule/Result) with 「〜ことにする」 (Personal Choice/Decision).
3. Context is King: Use it when discussing schedules, company rules, unavoidable outcomes, or reporting formal group decisions.

By consciously incorporating this structure into your writing and speaking practice, you will sound less like a textbook learner and more like a native speaker who understands the subtle but important dynamics of Japanese communication. Good luck with your JLPT preparation, and keep studying!

頑張ってください！ (Good luck!)

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