経過

1. Origins, structure, and basic meaning

• Structure: 経過 (けいか) is a noun that also forms a する verb for the course of a process or the passage of time.
• Basic usage: It describes how a condition develops after surgery or states that a measured period has elapsed.
  • 手術後の経過は順調だと医師が説明した。 — The doctor explained that recovery after surgery was progressing well.
  • 三十分が経過したので作業を終えた。 — Thirty minutes elapsed, so we finished the work.

2. Common pitfalls and similar expressions

• Course of progress and elapsed time
  • 手術後の経過 refers to the course of a changing condition, while 三十分が経過する describes time passing. Context distinguishes the noun and する verb uses.