形容詞 + to 不定式

很多形容詞後面可以接 to + 動詞原形，用來說明某個動作怎麼樣，或者你對它有什麼感受。主要有五種句型：

💡不要漏掉形式主語 it。英語句子必須有主語：It's difficult to learn English（不說：Is difficult to learn English）。

1. It's + 形容詞 + to + 動詞——對某個動作發表看法：easy、hard、difficult、important、necessary、possible、safe、dangerous、nice、great、expensive…

• It's important to drink enough water in hot weather.

  天熱的時候多喝水很重要。

• It isn't easy to find a cheap flat in Hanoi.

  在河內找到便宜的房子不容易。

• It was great to see you last weekend!

  上週末見到你真是太好了！

也可以用 -ing 形式作主語來代替 it。意思一樣，但用 it 的說法在口語中更自然：Finding a cheap flat isn't easy.

2. 加上做這件事的人：for + 人 + to + 動詞

• It's hard for me to understand his accent.

  他的口音我很難聽懂。

• It's normal for babies to wake up at night.

  嬰兒夜裡醒來是很正常的。

3. 評價某人的行為：It's + 形容詞 + of + 人 + to + 動詞——kind、nice、good、generous、thoughtful、silly、careless、rude…

• It's very kind of you to help me.

  你能幫我真是太好了。

• It was silly of me to leave my phone in the taxi.

  我真傻，把手機落在出租車上了。

4. 人 + 表示情緒的形容詞 + to + 動詞——某人對某事的反應：happy、glad、pleased、sorry、surprised、shocked、relieved、lucky、proud、disappointed…

• Nice to meet you.

  很高興認識你。

• I'm sorry to hear that you're ill.

  聽說你病了，我很難過。

• I was surprised to see Hung at the party.

  在聚會上見到阿雄，我很驚訝。

• We were lucky to get the last two tickets.

  我們很幸運，買到了最後兩張票。

5. 人 + 表示態度的形容詞 + to + 動詞——準備好、不願意、小心…：ready、willing、happy（= 樂意）、keen、afraid、careful、quick、slow…

• I'm ready to go.

  我準備好出發了。

• I'm happy to help if you need anything.

  你需要什麼的話，我很樂意幫忙。

• Be careful not to drop it.

  小心別把它摔了。（否定：not to + 動詞）

6. 物 + be + 形容詞 + to + 動詞——用它做某事有多容易、多難…。主語其實就是動詞的賓語，所以句末不要再加 it/them。

• This book is easy to read.

  這本書很好讀。（不說：easy to read it）

• His handwriting is hard to read.

  他的字很難認。

afraid：afraid to + 動詞 = 害怕得不敢主動去做某事（I was afraid to ask）；afraid of + -ing = 害怕某事可能發生（I'm afraid of falling）。口語中兩者常有重疊，但不帶 of 的 afraid + -ing 是錯的。I'm afraid (that)… 是委婉地告知壞訊息的說法——見“口語句式”一課。

sorry：sorry to + 動詞，用於正在發生的事或剛聽到的訊息（Sorry to bother you. / Sorry to hear that.）；sorry for + -ing 或 sorry (that) + 從句，用於你做過的事（Sorry for shouting.）。

• too + 形容詞 + to + 動詞 = 太……以至於不能：It's too hot to sleep. 見“‘too … to’ / ‘enough to’”一課。
• 形容詞 + enough + to + 動詞 = 足夠……可以：She's old enough to drive.
• the first / the last / the only (+ 名詞) + to + 動詞 = 第一個、最後一個或唯一一個做某事的人：Lan was the first person to arrive. / He's the only one to pass the test.

• The tea is too hot to drink.

  茶太燙了，沒法喝。

• Is your son old enough to ride a motorbike?

  你兒子到了可以騎摩托車的年齡嗎？

• She was the last to leave the office.

  她是最後一個離開辦公室的。

• ✗Is difficult to learn English.

  ✓It's difficult to learn English.

  英語需要形式主語 it。

• ✗It's hard for me understand his accent.

  ✓It's hard for me to understand his accent.

  for + 人後面仍然需要 to + 動詞。

• ✗I'm ready for go now.

  ✓I'm ready to go now.

  ready + to + 動詞；for 只接名詞（ready for dinner）。

• ✗It's dangerous to driving at night.

  ✓It's dangerous to drive at night.

  to 後面接動詞原形。

• ✗It's very kind for you to help me.

  ✓It's very kind of you to help me.

  稱讚某人的行為 → of。

• ✗This question is easy to answer it.

  ✓This question is easy to answer.

  主語已經是賓語了，不要重複 it。