安娜的隨想隨寫部落

不定詞(to + V)→V指的是原形動詞
當「主詞」用時，永遠指單一事件，所以動詞用單數。
英文句子中通常主詞都是名詞，如果主詞之中要出現動詞，則必須在動詞之前加to，這樣會把那個動詞變成名詞，也就是不定詞。
example: To exercise more is my plan for this summer. (多運動是我今年夏天的計畫)

如果不定詞所形成的主詞很長時，可以用虛主詞 it 代替主詞的位置，而將真正的主詞擺到後面。
example: To meet in front of the MRT station is convenient for us.
              = It is convenient for us to meet in front of the MRT station. (在捷運站前碰面對我們來說是方便的)

當受詞用時，英文句子中通常受詞都是名詞，如果受詞要出現動詞，同樣要把那個動詞變成不定詞(to+ V)。
example: I don't want to go home. (我不想回家)

使用不定詞當受詞的動詞：
decide, hope, need, want, plan, would like等→也就是這些字後面若要加動詞，一定要使用不定詞
example: I decided to make more money this year. (今年我決定要多賺點錢)
                  I hope to fulfill my dream. (我希望實現我的夢想)
                  You need to go home now. (你該回家了)
                  He would like to make friends with Amy. (他想跟Amy做朋友)

另外，可以同時用不定詞和動名詞當作受詞的動詞有love, like, hate，兩者意思相同
example: I love to play tennis.
               =I love playing tennis. (我喜愛打網球)

注意！不定詞的否定用法為not to+V
example: He told me not to open the door. (他要我別開門)
這裡常常會誤用為He told me don't open the door. 這種語法是錯誤的喔！

常用句型
too...to+V  (太...以至於不能...)
example: He is too shy to make a speech in public. (他太害羞以至於不能在公眾場所演說)
                 The student is too nervous to say a word. (這學生太緊張以至於說不出話來)

...enough to+V (足以...)
example: The room is big enough for us to sleep in. (這房間夠大夠我們睡)
                  You are old enough to go to school. (你已經夠大可以去上學了)