表す and 述べる: what conveys meaning and who states it
Identify the roles of a red line showing temperature changes, a letter expressing gratitude, and a person stating reasons or witnessed events.
What the red line shows
In 「赤い線は気温の変化を表している。」, the red line shows changes in temperature. The line is the subject of 表す, and temperature changes are the content it shows.
The sentence identifies what the line represents. Do not turn it into someone’s statement or add a separate numerical calculation or measurement result.
Gratitude expressed in a letter
「感謝の気持ちを短い手紙で表した。」 describes expressing gratitude in a short letter. 表す can involve language in a letter as well as a line or image.
The letter is the means of expression, and gratitude is the content expressed. Restricting 表す to nonverbal expression would exclude this letter example.
Who states which content with 述べる
「代表は計画に賛成する理由を述べた。」 identifies the representative as the person stating reasons for supporting the plan. It shows a person-and-content relationship, unlike the line representing changes.
「目撃したことを順番に述べてください。」 requests an account of witnessed events in order. It does not establish a completed account, and 述べる is not restricted to oral statements.
What are the subjects and the represented or stated content in 「赤い線は気温の変化を表している。」 and 「代表は計画に賛成する理由を述べた。」?
Show the answer and why
The red line shows temperature changes in the first sentence. The representative states reasons for supporting the plan in the second. Because 表す also occurs with a letter, do not impose an exclusive nonverbal-versus-verbal division between the verbs.