question

1. Origins, structure, and basic meaning

• Structure: 問 expresses asking or raising a question; its on-reading is もん, and its verb reading is とう.
• Basic usage: 質問 is read しつもん, and 疑問 is read ぎもん.

2. Common pitfalls and similar expressions

• A question asked and a doubt that remains
  • 先生に一つ質問した means that someone asked the teacher one question. It describes addressing someone to seek an answer.
  • 疑問が残った means that a question or doubt remained. Something can remain unclear, or a result can be doubted, even without asking another person a question.