中文的「在」一個字可以接所有時間：「在六月、在星期一、在七點」。但英文硬性分三個介系詞——in / on / at——台灣學生憑感覺亂代，Grammar 分數就卡 6.0。

為什麼是 Taiwanese 特有錯誤

母語沒有「時間介系詞的區別」這個概念，所以：

❌ I was born in Monday. ❌ The meeting is at June. ❌ I wake up on 7 am.

三種時間介系詞必須分開記——不能靠「感覺」。

三條鐵律

| 介系詞 | 用於 | 範例 | |--------|------|------| | in | 較長時間區段（月、年、季節、世紀、早午晚） | in June, in 2026, in winter, in the morning | | on | 特定日期、星期、節日 | on Monday, on 25 April, on my birthday | | at | 時間點、夜晚、節慶日（西方慣用） | at 7 pm, at noon, at night, at Christmas |

❌ Wrong vs ✅ Correct

| ❌ Wrong | ✅ Correct | |----------|-----------| | I was born in Monday. | I was born on Monday. | | The exam is at June 3rd. | The exam is on June 3rd. | | We meet on 7 pm. | We meet at 7 pm. | | I study on the morning. | I study in the morning. | | She called me in Sunday night. | She called me on Sunday night. | | Term starts on 2026. | Term starts in 2026. |

特殊組合要注意

  • at night 但 in the night 極少用——考試用 at night。
  • on Monday morning（日期 + 早午晚 = 整體用 on）。
  • at the weekend（英式）／ on the weekend（美式）——雅思兩個都接受。

Quick Drill — 10 句填空

填入 in / on / at：

  1. My flight leaves ___ 6 am ___ Friday.
  2. She was born ___ 1998 ___ December.
  3. We go skiing ___ winter, usually ___ January.
  4. The ceremony starts ___ noon ___ Saturday.
  5. I feel sleepy ___ the afternoon.
  6. He proposed ___ Valentine's Day.
  7. ___ the 21st century, everything changed.
  8. See you ___ midnight ___ New Year's Eve.
  9. The library closes ___ 9 pm ___ weekdays.
  10. ___ summer I usually travel.

Answer Key

| # | 答案 | 解釋 | |---|------|------| | 1 | at / on | 時間點用 at；星期用 on | | 2 | in / in | 年份跟月份都用 in | | 3 | in / in | 季節跟月份都用 in | | 4 | at / on | noon 是時間點；星期用 on | | 5 | in | 早午晚用 in（in the afternoon） | | 6 | on | 節日 + Day 用 on | | 7 | In | 世紀用 in | | 8 | at / on | midnight 時間點；節日用 on | | 9 | at / on | 時間點 + 星期組合 | | 10 | In | 季節用 in |

記住這一條

寫完作文 Ctrl+F 搜 "in"、"on"、"at"，每個時間片語檢查一次——九成 6.5 以下考生的扣分都出現在這三個字。

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