1. 不定詞:to + V

(1) 當名詞: 通常表意願或尚未完成的事。

例: To pass the exam is my goal. (通過考試是我的目標。)

例: To travel (travel) around the world is my dream. (環遊世界是我的夢想。)

*常連用名詞: plan (計畫), decision (決定), determination (決定), proposal (建議), attempt (企圖),
                      goal (目標), aim (目標), wish (希望), hope (希望), dream (夢想), ideal (理想)…等。

例: It is interesting to surf (surf) the Internet. (上網很有趣。)

例: I want to take a walk. (我想去散散步。)

*常連用動詞: cause (造成), allow (允許), permit (允許), advise (建議), persuade (說服), enable (使能夠), ask (請求), want (想要), expect (期望), intend (意圖)…等。

(2) 當形容詞: 修飾前面的名詞

例: I have three more pages to read. (我還有三頁要讀。)

例: I need someone to talk to. (我需要可以講話的對象。)

(3) 當副詞: 用來表目的

例: He works hard to earn some more money. (他努力工作，為了多賺一些錢。)

例: I keep quiet in order not to make her angry. (我保持安靜，以免她生氣。)