所為

せい

cause, reason, fault

JLPT N3

Character Breakdown

Understanding 所為 (せい)

The word 所為 (せい) is commonly used to indicate the cause, reason, or fault behind an event or situation. It often carries a nuance of blame or responsibility, whether justified or not.

Usage and Nuance

When you use 所為, you are typically pointing out what caused something to happen, often with a slightly negative connotation, such as a problem or failure. It can be used in both casual and formal contexts but tends to appear more in written or polite speech.

Common Collocations

  • 所為で: "because of" or "due to" — used to explain the cause of an event.
  • 所為だ: "it's because of" — used to assign cause or blame.
  • ~の所為にする: "to blame something/someone" — often used when someone is shifting responsibility.

Tips for Learners

Be careful not to confuse 所為 with similar words like 原因 (げんいん), which is a more neutral term for "cause." 所為 often implies fault or blame, so it is more subjective. Also, avoid overusing it in casual conversation where simpler expressions like せいで or せいだ might be more natural.

Understanding this word helps you express cause and effect with nuance, especially when discussing problems or reasons behind events.

Example Sentences

かれのちこくはねぼうのせいだ。

His being late is because he overslept.

てんきのせいでしあいがちゅうしになった。

The match was canceled due to the weather.

かのじょのしっぱいはじゅんびぶそくのせいではない。

Her failure is not due to lack of preparation.