第十二週：語態助動詞 文法時間： 語態助動詞的形式 下表所列之動詞為情態助動詞，用來幫助動詞 表達各種意思 ( 如能力、應允、可能性、必須 性等。 ) 大部分的情態助動詞都有一種以上的 意思

助動詞 + 原型動詞 can, could, may, might, should, had, better, must, will, would 後面接原形動詞。 這些情態助動詞後面不接 to 正確： I can speak English. 錯誤： I can to speak English. 主要動詞的結尾不可加 -s 正確： Olga can speak English. 錯誤： Olga can speaks English. can (a)I can speak English. could (b)He couldn’t come to class. may (c)It may rain tomorrow. might (d)It might rain tomorrow.

Summary Chart of Modals and Similar Expressions. AuxiliaryUsesPresent/FuturePast may(1)polite request May I borrow your pen? (2)formal permission You may leave the room. (3)less than 50% certainty Where’s John? He may be at the library. He may have been at the library.

mightless than 50% certainty He might be at the library. polite request(rare) Might I borrow your pen? have to(1)necessityI have to (should) go to class today. I had to go to class yesterday. (2)lack of necessity(ne gative) I don’t have to go to class today. I didn’t have to go to class yesterday.

couldpast abilityI could run fast when I was a child. polite requestCould I borrow your pen? suggestionI need help in math. You could talk to your teacher. You could have talked to your teacher. less than 50% certainty Where is John? He could be at home. He could have been at home. Impossibility(ne gative only) That couldn’t be true. That couldn’t have been true.

錯誤範例： Sunrise and Sunset In my opinion, the most beautiful times of the day are sunrise and sunset. It (A) should not true for you, but I really think so. They are not only colorful, but are usually quiet and peaceful. I (B) ___want to stay at that time forever. Watching the sun rise and set gives me a chance to think about life.

I often watch the sunrise. When I see the sky light up, I know a new day is beginning. I feel as if the world has come back to life. This quiet time enables me to think about the day ahead of me. Furthermore, the beautiful scene inspires me to do my best, and to study hard. As the sun rises higher and becomes brighter, and I (C) might feel the strength of its energy.

The sun set gives me a very different feeling, though. It is sometimes even more beautiful than the sun rise. It makes me think about my life and my future. Our lives are short, and eventually we all must die. Accordingly, we (D) could use our time well. We (E) do also cherish what we have. This is what I learned from watching the sun set.

修改重點： (A) 將 should 改成 may 或 could 。此處要表達的 語氣為可能性，因此要用 may 或 could 。 (B) 將 might 去掉。因為 might 表達 2 種語態，第 一種為低於 50% 可能性，第二種為客氣的請求， 此處皆不需要此種語氣。

(C) 將 might 改成 can 。此處作者要表達的是可 以感覺到，是表能力的語氣，因此要用 can 。 (D) 將 could 改成 should 。作者要表達的語氣是 我們應該善用我們的時間 ”use our time well.” 表達必須性的口氣，因此要用 should 。 (E) 將 do 改成 should 。因為句中有 also ，同上句 語態，所以同用 should 。

修改後範例： Sunrise and Sunset In my opinion, the most beautiful times of the day are sunrise and sunset. It may not true for you, but I really think so. They are not only colorful, but are usually quiet and peaceful. I ___want to stay at that time forever. Watching the sun rise and set gives me a chance to think about life.

I often watch the sunrise. When I see the sky light up, I know a new day is beginning. I feel as if the world has come back to life. This quiet time enables me to think about the day ahead of me. Furthermore, the beautiful scene inspires me to do my best, and to study hard. As the sun rises higher and becomes brighter, and I can feel the strength of its energy.

The sun set gives me a very different feeling, though. It is sometimes even more beautiful than the sun rise. It makes me think about my life and my future. Our lives are short, and eventually we all must die. Accordingly, we should use our time well. We should also cherish what we have. This is what I learned from watching the sun set.