JLPT N1 Grammar: ～せいで・～せいか

By ProDev Teach | Updated May 2025

📘 Meaning & Usage

The expressions ～せいで and ～せいか are used to indicate causes or reasons, often for negative outcomes.

Structure:

• Verb (plain form) + せいで / せいか
• い-adjective (plain form) + せいで / せいか
• な-adjective + な + せいで / せいか
• Noun + の + せいで / せいか

Meanings:

• ～せいで: “Because of ~” (used when a specific cause leads to a negative result)
• ～せいか: “Perhaps because of ~” (used when the cause is uncertain)

💡 Example Sentences

• 雨のせいで、試合が中止になった。
  Because of the rain, the game was canceled.
• 彼の言い方のせいで、誤解が生じた。
  His way of speaking caused a misunderstanding.
• 寝不足のせいか、今日は集中できない。
  Perhaps because of lack of sleep, I can’t concentrate today.
• 薬を飲んだせいで、眠くなってきた。
  Because I took medicine, I started feeling sleepy.
• 運動不足のせいか、最近太ってきた。
  Perhaps due to lack of exercise, I’ve been gaining weight recently.

📝 Grammar Notes

• ～せいで is used when a specific cause leads to a negative result.
• ～せいか is used when the cause is uncertain or speculative.
• These expressions often convey a sense of blame or dissatisfaction.
• They are not typically used for positive outcomes; for positive causes, use ～おかげで.

📝 Practice Exercises

1. Fill in the blanks with ～せいで or ～せいか

1. 風邪をひいた＿＿＿＿、声が出ない。
2. 天気が悪い＿＿＿＿、気分が沈んでいる。
3. 彼の態度の＿＿＿＿、皆が不快に感じた。

✔ Answers:

• せいで
• せいか
• せいで

2. Translate into Japanese using ～せいで or ～せいか

1. Because I was late, I missed the meeting.
2. Perhaps due to stress, I can’t sleep well.
3. Because of the noise, I couldn’t concentrate.

✔ Sample Answers:

• 遅れたせいで、会議に出られなかった。
• ストレスのせいか、よく眠れない。
• 騒音のせいで、集中できなかった。

📚 Related Grammar

• ～おかげで: “Thanks to ~” (used for positive outcomes)
• ～ために: “Because of ~” (used for both positive and negative outcomes)
• ～ので: “Because ~” (neutral cause)

🧠 Summary

• Meaning: “Because of ~” (negative outcome) / “Perhaps because of ~” (uncertain cause)
• Structure: Verb/Adjective/Noun + せいで / せいか
• Nuance: Indicates a cause leading to a negative or undesirable result; せいか adds uncertainty.
• JLPT Level: N3

thuandao

I’m a software engineer based in Japan, with experience in developing web and mobile applications. I’m passionate about technology, especially in DevOps, AI, and app development using platforms like AWS, Flutter, and Node.js. My goal is to build a website that shares knowledge about the Japanese language and IT, helping everyone learn and grow more easily in the digital era.