✨ Basic Meaning
🎯 Primary Function
📋 Grammar Structure
🎭 Usage Contexts
Used in relatively neutral to slightly informal contexts. Less common in highly formal writing or speeches where more objective or polite expressions for cause might be preferred.
Very common in daily conversation, especially when complaining or explaining why something bad happened.
Common in casual writing like emails, blogs, or diaries. Less frequent in formal reports or academic papers unless expressing a clear point of blame.
Highly frequent in everyday spoken Japanese.
💡 Common Applications
📌 Important Points
⚠️ Common Mistakes
🏛️ Cultural Context
🔍 Subtle Differences
📝 Conjugation Notes
Verbs: Plain form (past or non-past). い-Adjectives: Stem form. な-Adjectives: + な. Nouns: + の.
🔊 Pronunciation Tips
「せいで」 is pronounced as “seide”. The で is pronounced clearly, not reduced like some other particles.
🧠 Memory Tips
Think of 「せいで」 as “This happened because of [cause], and I’m not happy about it!” Associate 「せい」 with negative “blame” or “fault”.

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.