N4Chapter 37

Expressing Reason & Cause

Learning Objectives

  • Review the subjective reason particle 〜から.
  • Learn the objective and polite reason conjunction 〜ので.
  • Use the て-form to express emotional reactions and light causes.
  • Understand the dual nature of 〜ために (Cause vs. Purpose).
N4 Context

In N5, you learned that 〜から means “because.” However, if you apologize to your boss using 〜から, it might sound entirely too defensive or subjective! Japanese has different grammar points for subjective reasons, objective facts, emotional triggers, and formal written causes. Mastering these nuances is key to sounding polite and professional.

1. Subjective Reason: 〜から

〜から attaches directly to the end of a sentence. It places the focus heavily on the speaker’s personal opinion, will, or subjective judgment. Because it is subjective, it naturally pairs with commands, requests, or personal intentions.

Grammar Point
[Sentence 1] から、[Sentence 2]。
MeaningBecause [Sentence 1] (subjective reason), [Sentence 2].
Formation:
Plain/Polite Form + から
Examples (3)
Example

危ないから、触らないでください。

abunai kara, sawaranaide kudasai.

Because it is dangerous, please do not touch it.

Example

明日テストがあるから、今夜は勉強します。

ashita tesuto ga aru kara, konya wa benkyou shimasu.

Because there's a test tomorrow, I will study tonight.

Example

美味しいから、たくさん食べてね。

oishii kara, takusan tabete ne.

Because it's delicious, eat a lot, okay?

2. Objective & Polite Reason: 〜ので

〜ので is the polite, objective counterpart to 〜から. It presents the reason as a natural sequence of events or a universally understood fact. It is the preferred way to state reasons in business, formal requests, and apologies.

Formation Rules:

  • Verbs & i-Adjectives: Plain form + ので
  • Na-Adjectives & Nouns: Add な before ので (e.g., 静かなので、雨なので)
Grammar Point
[Sentence 1] ので、[Sentence 2]。
MeaningSince/Because [Sentence 1] (objective reason), [Sentence 2].
Formation:
Plain Form + ので (Noun/Na-Adj + なので)
Examples (3)
Example

お腹が痛いので、先に帰らせていただきます。

onaka ga itai node, saki ni kaerasete itadakimasu.

Since my stomach hurts, I will (humbly) go home first.

Example

バスが遅れたので、会議に遅刻しました。

basu ga okureta node, kaigi ni chikoku shimashita.

Since the bus was delayed, I was late for the meeting.

Example

今日は日曜日なので、銀行は休みです。

kyou wa nichiyoubi na node, ginkou wa yasumi desu.

Since today is Sunday, the bank is closed.

[!WARNING] Because 〜ので is an objective statement of fact, you generally cannot follow it with a strong personal command like 〜しなさい. Use 〜から for direct commands!

3. Light Cause/Emotional Trigger: て-form / で

You can use the て-form of a verb or adjective (or で for nouns) to indicate a natural, light cause. This is used when the result is an uncontrollable emotion or a natural state.

Grammar Point
[A て-form]、[B]。
MeaningBecause of A, B naturally happened/was felt.
Formation:
Verb-te / Adj-kute / Noun-de
Examples (3)
Example

ニュースを聞いて、びっくりしました。

nyuusu o kiite, bikkuri shimashita.

I heard the news and was surprised.

Example

試験が難しくて、わかりませんでした。

shiken ga muzukashikute, wakarimasen deshita.

The exam was difficult, so I didn't understand it.

Example

風邪で、学校を休みました。

kaze de, gakkou o yasumimashita.

Because of a cold, I was absent from school.

4. Formal Cause & Purpose: 〜ために

〜ために is formal and has two meanings depending on the context:

A. Formal Cause (Due to)

Example

大雨のために、電車が止まっています。

ooame no tame ni, densha ga tomatte imasu.

Due to heavy rain, the train is stopped.

B. Purpose (In order to)

Example

留学するために、お金を貯めています。

ryuugaku suru tame ni, okane o tamete imasu.

In order to study abroad, I am saving money.
Example

健康のために、毎日走っています。

kenkou no tame ni, mainichi hashitte imasu.

For the sake of health, I run every day.

Cultural Insight: The Art of the Japanese Excuse

In Japanese culture, providing a reason is not just about giving information; it’s about maintaining social harmony (Wa). Using 〜から for an excuse can sound like you are trying to justify your actions or blame external factors.

By contrast, using 〜ので suggests that the situation was a natural occurrence beyond your control, which sounds humbler and more apologetic. This is why in service industries or workplace apologies, you will almost exclusively hear 〜ので. Even if you are late because you overslept, saying 寝坊したので (Since I overslept) sounds softer than 寝坊したから.

Contextual Dialogues

Dialogue 1: At the Office

Arriving Late
Tanaka

鈴木さん、遅いですね。会議はもう始まっていますよ。

Suzuki-san, osoi desu ne. Kaigi wa mou hajimatte imasu yo.

Suzuki-san, you're late. The meeting has already started.

Suzuki

申し訳ありません。事故で電車が止まってしまったんです。

Moushiwake arimasen. Jiko de densha ga tomatte shimatta n desu.

I'm very sorry. Due to an accident, the train stopped.

Tanaka

そうですか。部長が心配していたので、後で謝っておいてくださいね。

Sou desu ka. Buchou ga shinpai shite ita node, ato de ayamatte oite kudasai ne.

I see. Since the manager was worried, please apologize later.

Dialogue 2: Planning a Trip

Travel Preparation
Suzuki

来週、北海道へ行くんです。

Raishuu, Hokkaidoo e iku n desu.

I'm going to Hokkaido next week.

Tanaka

いいですね！雪まつりを見るためですか。

Ii desu ne! Yuki-matsuri o miru tame desu ka.

Wow! In order to see the snow festival?

Suzuki

ええ。有名だから、どうしても見たいんです。

Ee. Yuumei da kara, doushitemo mitai n desu.

Yes. It's famous, so I really want to see it.

Tanaka

北海道は寒いので、気をつけてくださいね。

Hokkaidoo wa samui node, ki o tsukete kudasai ne.

Hokkaido is cold, so please be careful.

Chapter Summary

Key Takeaways
  • 1〜から: Subjective reason, focuses on speaker's will/judgment.
  • 2〜ので: Objective reason, polite, used for apologies and formal requests.
  • 3て-form: Light cause for emotions, inability, or natural states.
  • 4〜ために: Formal cause (due to) or purposeful action (in order to).
  • 5Choice of reason particle affects politeness and perceived sincerity.

Knowledge Check

Practice Quiz
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Quiz

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Which is the most appropriate way to apologize for being late to a formal meeting?