Explanation
Use "do", "does", or "did" in a wh-question when the main verb is not "be". Put the wh-word first, then the helper, then the subject, then the base verb.
For example, "Where did you buy this bag?" Here "Where" asks about the place, "did" shows the past, "you" is the subject, and "buy" is the base verb. In Japanese, you can often ask the same thing with no helper word. English needs this extra word order. With "does", do not add "-s" to the main verb: "What does she want?"
wh 疑問文では、be 動詞以外の文で "do / does / did" を使います。wh 語を最初に置き、そのあとに "do / does / did"、主語、動詞の原形を続けます。
たとえば "Where did you buy this bag?" では、"Where" が場所、"did" が過去、"you" が主語、"buy" が原形です。日本語では「どこで買ったの？」のように助動詞なしで言えます。英語ではこの語順が必要です。"does" を使うときは、動詞に "-s" を付けません。
Examples
- Where do you live? どこに住んでいますか。
- What does she want for lunch? 彼女は昼ごはんに何がほしいですか。
- Why do we need this app? なぜこのアプリが必要なのですか。
- When did you start this job? いつこの仕事を始めましたか。
- Where did they have dinner? 彼らはどこで夕食を食べましたか。
- Why didn't he call you? なぜ彼はあなたに電話しなかったのですか。
Common Mistakes
Japanese learners often skip "do / does / did" and keep statement order.
Wrong: "What you want?"
Right: "What do you want?"
They also use the wrong verb form after "did".
Wrong: "When did you went home?"
Right: "When did you go home?"
日本語の語順のまま、"do / does / did" を抜かしてしまうことがよくあります。
誤り: "What you want?"
正しくは: "What do you want?"
また、"did" のあとに過去形を置いてしまうこともあります。
誤り: "When did you went home?"
正しくは: "When did you go home?"