一句話用法：形容影響、改變、洞察的深度時用 profound——比 big 學術、比 deep 精準。
意思
Profound (adj.) = 深刻的、深遠的、強烈的（多用於影響、變化、思想）。
跟字面的 deep（深的水池）不同——profound 專指抽象的深度：影響的深遠、思想的深度、感受的強烈。
自然搭配
- The pandemic had a profound impact on how we work and learn.
- His teaching had a profound influence on a whole generation of students.
- Living abroad for a year brought about profound changes in her worldview.
- The book offers profound insights into the human condition.
- Climate change is causing profound shifts in global weather patterns.
幾個高頻搭配——profound impact / influence / change / insight——背起來直接套。
學生常犯的錯
把 profound 當作 deep 的萬用替換：
The lake is very profound. ← 錯（具體深度用 deep） His ideas are very profound. ← 對（抽象深度）
口訣：profound 配抽象，deep 配具體。
另一個錯——profound 過度使用：
I have a profound headache. ← 過頭（用 severe） He has a profound understanding of the topic. ← 自然
profound 偏正向、智性、嚴肅的場合——不是任何「強烈」都能用。
Band 7 同義替換
避免一篇文章 profound 出現三次，輪流用：
- far-reaching——far-reaching consequences（更強調「影響範圍廣」）
- significant（最安全的退階）
兩個並用：講影響時 profound impact，講後果時 far-reaching consequences——同一個段落兩種說法。
試試看
升級這句：
The internet has changed our lives a lot. → The internet has had a profound and lasting impact on modern society.
換 had a profound impact——句子結構也升級。
延伸閱讀：Band 6 → 7 詞彙升級