分辨語氣
知道 should 比較像建議，must 比較像必要或規定。
Day 13｜助動詞：should / must
這一章要學 should 和 must，分清楚「應該」和「必須」的語氣差別。
學
本章學習目標
會寫句型
會寫 should / must 的肯定句、否定句和問句。
注意原形
知道這兩個後面都接原形動詞。
1
白話解釋
should 比較像「應該」，語氣比較輕，常用在建議。
must 比較像「必須」，語氣比較強，常用在規定或很重要的事。
生活例子
You should go to bed early. 你應該早點睡。
Students must wear uniforms. 學生必須穿制服。
2
常見錯誤
錯誤 1：後面加 s
He should studies more.
He should study more.
should 後面接原形動詞。
錯誤 2：後面加 to
We must to leave now.
We must leave now.
must 後面不用 to。
錯誤 3：把語氣用反
You should stop at a red light.
You must stop at a red light.
紅燈停車是規定，語氣更強，多半用 must。
3
正確句型
肯定句
主詞 + should / must + 原形動詞
You should rest. / We must hurry.
否定句
主詞 + should not / must not + 原形動詞
You shouldn't be late. / You must not run here.
疑問句
Should / Must + 主詞 + 原形動詞 ... ?
Should I call her? / Must we finish it today?
4
例句
- You should drink more water. 你應該多喝水。
- I should do my homework first. 我應該先寫功課。
- We must be quiet in the school library. 我們在圖書館必須安靜。
- Students must not use phones in class. 學生上課不能用手機。
- Should I open the window? 我應該把窗戶打開嗎？
5
練習題
練習說明：下面 5 題是改錯題，請把 should / must 句型改正。
- You should goes home early.
- We must wear helmets.
- He must to finish the work today.
- Students should be polite.
- Must you to leave now?
答
答案與解析
- You should go home early.
解析：should 後面要接原形動詞 go。
- We must wear helmets.
解析：這題本來就是正確句子。
- He must finish the work today.
解析：must 後面不用 to。
- Students should be polite.
解析：這題本來就是正確句子。
- Must you leave now?
解析：問句時 must 放前面，後面的動詞用原形 leave。
導