最中に— Right in the Thick of It

• 食事の最中に電話がかかってきた。

  Shokuji no saichuu ni denwa ga kakatte kita.

  The phone rang right in the middle of the meal.

  Noun 食事 + の + 最中に marks the meal as the ongoing event interrupted by the call.

• 会議をしている最中に、地震が起きた。

  Kaigi wo shite iru saichuu ni, jishin ga okita.

  An earthquake struck right while we were in the middle of the meeting.

  Verb ている form している + 最中に stresses the meeting was at full swing when interrupted.

• 試験の最中に急にお腹が痛くなった。

  Shiken no saichuu ni kyuu ni onaka ga itaku natta.

  Right in the middle of the exam, my stomach suddenly started hurting.

  の最中に highlights the worst possible timing during the exam.

• ・Almost always followed by a sudden, disruptive, or unwelcome event.
• ・最中に needs an action of some duration; it cannot mark an instantaneous moment.
• ・Casual speech often shortens it to 〜最中 (saichuu) without に at the end of a clause.

Commonly confused with

The JLPT rarely asks whether you recognise a pattern — it asks which of several similar patterns fits. These are the ones 最中に is tested against.

• ～ないうちに — Before It Happens
• ～上(で) — After Doing / In the Process Of
• ～から～にかけて — Spanning From To
• ～際(に) — On The Occasion Of
• 次第 — The Moment It's Done
• ～て以来 — Ever Since Then
• ～ところに／～ところへ — Right At That Moment
• ～ところを — Caught In The Act