第 110 課 · 第 9 階段: 連線觀點
“unless / in case / as long as”
中級“Unless / in case / as long as”
構成與用法
unless, in case, as long as, provided that, even if — 表達條件的其他方式
1.概述
除了 if，英語還有好幾個表示條件的連線詞，每個都有自己的意思。
| 連線詞 | 意思 | 例句 |
|---|---|---|
| unless | 除非（= if … not） | I'll walk unless it rains. |
| in case | 以防（因為某事可能發生） | Take a jacket in case it gets cold. |
| as long as / so long as | 只要（滿足這個條件） | You can go as long as you're back by ten. |
| provided (that) / providing (that) | 只要（更正式） | You can park here provided you have a permit. |
| even if | 即使（不管這件事發不發生） | I'll go even if it rains. |
和 if 一樣，這些詞後面都用現在時表示將來，不用 will：in case it rains（不說：in case it will rain），unless you come（不說：unless you will come）。
2.Unless = if … not
Unless 本身已經含有否定意思（“如果不”“除非”），所以後面的動詞通常是肯定形式。
Unless we leave now, we'll be late.
除非我們現在就走，否則會遲到。（= If we don't leave now…）
I won't call you unless there's a problem.
除非有問題，否則我不會給你打電話。
Don't touch that unless you know what you're doing.
除非你知道自己在做什麼，否則別碰那個。
Do you need a coat? — Not unless it gets really cold.
你需要外套嗎？——除非天特別冷，否則不用。
- 當條件是唯一的例外時才用 unless。有些 if … not 的句子不能換成 unless，特別是表達對某事沒有發生的感受時：I'll be upset if you don't come（不說：unless you come）。
- 疑問句一般用 if，不用 unless：What will you do if you don't pass?
3.In case = 以防
In case 說明現在做某事的原因：為以後可能發生的事做好準備。
Save the file now in case the computer crashes.
現在就儲存檔案，以防電腦宕機。
Take a photo of your passport in case you lose it.
把護照拍張照，以防丟了。
In case 和 if 不一樣。比較：
I'll cook extra rice in case your friends come.
我多煮點飯，以防你朋友來。（不管他們來不來，我現在都煮）
I'll cook extra rice if your friends come.
如果你朋友來，我就多煮點飯。（他們來了我才煮）
- just in case = 以防萬一（可能性更小）：I don't think we'll need it, but I'll bring a charger just in case。
- in case + 過去時 解釋你過去做某事的原因：I gave her my number in case she needed help。
- in case of + 名詞 = 如果發生……（常見於標誌和說明）：In case of fire, use the stairs。
- 在美式英語中，in case 有時用起來幾乎和 if 一樣：In case you need me, I'm in my office。學習時，最好按上面的方法把兩種意思分開。
4.As long as / provided (that)
這幾個詞表示嚴格的條件：只有滿足這個條件，結果才會發生。As long as / so long as 在口語中很常見；provided (that) / providing (that) 更正式，常見於規定和合同。
You can borrow my laptop as long as you're careful with it.
只要你小心使用，就可以借我的筆記型電腦。
As long as you practise every day, your speaking will improve.
只要每天練習，你的口語就會進步。
Guests may use the pool provided that they shower first.
客人須先淋浴，方可使用泳池。
I'll lend you the money, providing you pay me back next month.
我借錢給你，只要你下個月還我。
As long as 也可以表示時間，“在……的整個期間”：You can stay as long as you like。要讀完整句話，才能判斷它表示條件還是時長。
5.Even if = 不管會不會
Even if 表示不管條件是否發生，結果都一樣。不要和 even though 混淆，even though 說的是事實（見“Although / though / despite”一課）。
I'm going to the beach even if it rains.
即使下雨，我也要去海邊。（我們還不知道會不會下雨）
Even if we leave now, we won't get there on time.
即使我們現在就走，也來不及準時趕到了。
Even though it was raining, we went to the beach.
儘管在下雨，我們還是去了海邊。（當時確實在下雨）
6.常見錯誤
Unless you don't study, you will fail the test.Unless you study, you will fail the test. / If you don't study, you will fail the test.
Unless 本身已經含有否定意思。
Bring a jacket in case it will get cold.Bring a jacket in case it gets cold.
in case 後面用現在時表示將來。
I won't go unless you will come with me.I won't go unless you come with me.
unless 後面不用 will。
Take an umbrella in case of it rains.Take an umbrella in case it rains. / … in case of rain.
In case + 從句；in case of + 名詞。
Even it rains, we'll play football.Even if it rains, we'll play football.
要用 even if，不能只用 even。
Even though it rains tomorrow, I'll go.Even if it rains tomorrow, I'll go.
不知道會不會下雨 → 用 even if。
例句
- You can't come in unless you have a ticket.
- Unless you hurry, you'll miss the bus.
- We'll have the party in the garden unless it rains.
- Take an umbrella in case it rains later.
