Translation guide
The English word 'because' introduces a reason or cause. In Japanese, the most common equivalent is から (kara), but other forms like ので (node), ため (tame), and て (te) are used depending on formality, politeness, and sentence structure. This guide covers the main ways to express 'because' in Japanese, organized by usage.
Express a reason or cause in everyday conversation or informal writing.
Attach to the plain form of verbs, i-adjectives, na-adjectives (add だ), and nouns (add だ). This is the most common and versatile way to say 'because'. It can be used at the end of a sentence or before the main clause.
雨が降っているから、出かけません。
Because it's raining, I won't go out.
Because I'm tired, I'll go to bed early.
Used to list multiple reasons, often implying there are other reasons too. It can soften the statement. Attach to plain form.
雨も降っているし、寒いし、家にいよう。
It's raining, and it's cold, so let's stay home. (Implies these are some of the reasons.)
Express a reason in polite conversation, business settings, or formal writing.
Attach to the plain form of verbs, i-adjectives, na-adjectives (add な), and nouns (add な). It sounds softer and more polite than から. Often used when the reason is an objective fact or when making a polite request.
電車が遅れたので、遅刻しました。
Because the train was late, I was late.
明日は忙しいので、今日中にお願いします。
Because I'm busy tomorrow, please do it by today.
Used in formal writing or speech. It can express cause/reason (often negative outcomes) or purpose. For reason, attach to plain form of verbs/adjectives. に is often omitted in causal usage.
台風のため、電車が止まりました。
Because of the typhoon, the trains stopped.
事故があったため、遅れました。
Because there was an accident, I was late.
Express 'because of [noun]' or 'due to [noun]'.
Used to blame something or someone for a negative outcome. It carries a nuance of fault. Attach to a noun or plain form of verb/adjective + の.
Using せい for positive outcomes is unnatural. Use おかげで for positive reasons.
雨のせいで、ピクニックが中止になった。
Because of the rain, the picnic was canceled. (blaming the rain)
Used to express gratitude or a positive reason. 'Thanks to [noun]'. Attach to a noun or plain form + の.
あなたのおかげで、成功しました。
Thanks to you, I succeeded.
Neutral/formal 'because of [noun]'. Often used in news or formal contexts.
雪のため、学校が休みになった。
Because of the snow, school was closed.
Express a reason or cause using the te-form of verbs/adjectives, often implying a natural consequence or emotional reaction.
Provide an explanation or reason in a conversational, explanatory tone.
Used to explain a reason or situation, often in response to a question or to provide context. んです is spoken, のです is written/formal. Attach to plain form (na-adj/noun + な).
どうして遅れたんですか？ ― 電車が遅れたんです。
Why were you late? — Because the train was late.
頭が痛いんです。
I have a headache (explaining why I look unwell).
Start a new sentence with 'because of that' or 'therefore'.
Casual conjunction meaning 'so' or 'therefore'. Used at the beginning of a sentence.
今日は雨だ。だから、傘を持っていく。
It's raining today. So, I'll take an umbrella.
Polite version of だから.
Formal 'for that reason' or 'because of that'. Used in writing or formal speech.
から is more subjective and direct, often used for personal reasons or strong assertions. ので is more objective and polite, often used for factual reasons or when making requests. In formal writing, ので is preferred. In casual speech, から is more common.
寒いから、窓を閉めて。
Close the window because it's cold. (direct, casual)
寒いので、窓を閉めていただけますか。
Could you close the window because it's cold? (polite request)
なぜなら (nazenara) means 'because' but is very formal and literary. It is rarely used in everyday conversation. Stick to から or ので for most situations.
The te-form can express a reason when followed by words like 嬉しい (happy), 悲しい (sad), 困る (be troubled), 助かる (be helped), etc. It often implies a cause-and-effect relationship without explicitly saying 'because'.
病気だったから、行かなかった。
I didn't go because I was sick.
休日なので、店は閉まっています。
Because it's a holiday, the store is closed.
手伝ってくれたおかげで、早く終わった。
Thanks to your help, I finished early.
電車が遅れました。ですから、遅刻しました。
The train was late. Therefore, I was late.
Demand increased. Because of that, prices rose.