一句話用法：講「程度大到值得注意」的影響、變化、差異——比 important 更學術、更精準。
意思
Significant (adj.) = 顯著的、值得注意的、影響重大的。中文「重要」涵蓋太廣——significant 專指程度足夠大、可被觀察或測量的那種重要。
自然搭配
最常見的固定搭配，背起來直接套：
- There has been a significant increase in the number of remote workers since 2020.
- Air pollution has a significant impact on respiratory health, particularly in urban areas.
- The two groups showed significant differences in their reading habits.
- Renewable energy now plays a significant role in the national grid.
- Although the policy was popular, it had no significant effect on actual emissions.
注意 a significant + 名詞 的結構——比「very important」精準十倍。
學生常犯的錯
很多學生把 significant 當作「有意義」用：
This day is very significant for me.（指「對我有意義」）
雖然文法沒錯，但在 IELTS 學術寫作裡，significant 應該指可觀察的程度，不是情感意義。寫情感意義時用 meaningful 或 memorable 更自然。
另一個錯誤——把 significant 跟數字搭配時忘了加比較基準：
The price rose significantly.（OK） The price rose a significant amount.（更精準，常用於 Task 1）
Band 7 同義替換
當你已經用過一次 significant，下次換成：
- considerable——a considerable proportion of households
- substantial——a substantial decrease in carbon emissions
兩個字幾乎可互換，但 substantial 更偏「數量大」，considerable 更偏「程度顯著」。
試試看
把這句話改寫得更專業：
Many people think this is a very important problem. → This is widely regarded as a significant issue.
延伸閱讀：Band 6 → 7 詞彙升級