成なり代かわる

godan verb (-ru), intransitive verb

take over for; stand in for; substitute for

Used when a person temporarily or permanently takes over another person's role, duty, or position. Often implies acting on behalf of someone else.

• 急きゅうに社しゃ長ちょうが倒たおれたので、副ふく社しゃ長ちょうが成なり代かわって会かい議ぎを進すすめた。

  Since the president suddenly collapsed, the vice president took over and proceeded with the meeting.

• 母ははが病びょう気きのときは、私わたしが成なり代かわって家か事じをした。

  When my mother was sick, I stood in for her and did the housework.

godan verb (-ru), intransitive verb

replace; take the place of

Used when one thing or person replaces another, often implying a change in state or function. Can be used for objects, roles, or abstract concepts.

• 古ふるい制せい度どに成なり代かわって、新あたらしいルールが導どう入にゅうされた。

  New rules were introduced, replacing the old system.

• 紙かみの辞じ書しょに成なり代かわって、電でん子し辞じ書しょが主しゅ流りゅうになった。

  Electronic dictionaries have taken the place of paper dictionaries and become mainstream.