Explanation
Use "who" for the subject of a question. Use "whom" for the object, but it sounds formal and old-fashioned in everyday speech.
For example, in "Whom did you invite to the party?", "whom" is the person who receives the action. "Did" shows the past question, and "invite" stays in the base form. In normal conversation, many people say "Who did you invite to the party?" instead. Japanese does not change the pronoun form for subject and object, so this difference is easy to miss.
質問では、主語なら "who"、目的語なら "whom" を使います。ただし "whom" は日常会話ではかなりフォーマルで、少しかたい響きがあります。
たとえば "Whom did you invite to the party?" では、"whom" が招待された人を表します。"did" が過去の疑問文を作り、"invite" は原形のままです。ふつうの会話では "Who did you invite to the party?" の方が自然です。日本語は主語と目的語で形が変わらないので、この違いは見えにくいです。
Examples
- Who is that man? あの男性はだれですか。
- Who called you last night? 昨夜、だれがあなたに電話しましたか。
- Who did you see at the station? 駅でだれに会いましたか。
- Whom did you invite to dinner? 夕食にだれを招待しましたか。
- To whom should I give this form? この用紙はだれに渡せばいいですか。
- I don't know who left the lights on. だれが電気をつけっぱなしにしたのか分かりません。
Common Mistakes
Japanese learners often use "whom" as the subject of a question.
Wrong: "Whom is at the door?"
Right: "Who is at the door?"
In modern English, "whom" is for the object, not the subject. In speech, "who" is usually the natural choice unless you want a very formal tone.
日本語話者は、"whom" を "who のかしこまった形" だと思って、主語にも使いがちです。誤り: "Whom is at the door?" 正しくは "Who is at the door?" です。現代英語では、"whom" は主語ではなく目的語に使います。会話では、特にフォーマルにしたい場合を除き、"who" の方が自然です。