用demand後, 為何he/she/it 後的動詞不用加s？

問：I ______ that she come here soon.
A. suppose
B. demand
C. think
D. believe
答案為B(demand), 但我不明白這裡為什麼出現了she come, 而不是she comes.

答：英語裡凡表示要求、建議、意圖、決定、推薦等意義的動詞, 在正式英語裡, 尤其是在美式英語裡, 要求其受詞子句使用現在式假設語氣(其特徵是: 無第三人稱變化, 也無時態變化) :

1. I demand that John go there at once.
   我要求約翰馬上去那兒。
2. The employees have demanded that the manager resign.
   雇員們要求經理辭職。
3. They demanded that the right to vote be given to every adult man.
   他們要求每個成年人都應有選舉權。

具有這種文法特徵的動詞還有: decide (決定), ask (要求), insist (堅持), order (命令), prefer (寧願), propose (提議), recommend (推薦、建議), require (要求), request (請求), suggest (建議), desire (希望得到) 。下面讓我們舉一些例子:

1. I ask that he leave.
   我請他離開。
2. I insist that he go.
   我堅持讓他走。
3. The king ordered that the man be released.
   國王下令釋放這個人。
4. Would you prefer that I come on Monday instead of on Tuesday?
   你是否希望我星期一而不是星期二來?
5. I propose that Mr. John O’Leary be the chairman.
   我提議讓約翰·奧利裡先生做主席。
6. I recommend that everyone buy this dictionary.
   我建議大家都買這本字典。
7. He requires that they work all night.
   他要求他們整夜工作。
8. She suggested that I be responsible for the arrangement.
   她建議我負責安排這件事。
9. She desires that you come at once.
   她希望你能馬上來。

但是, 應當注意, 在英式英語中則常常採用should be 的形式:

1. I asked that I should be allowed to see her.
   我請求允許我去看她。
2. I insisted that he should come with us.
   我堅持他和我們一起去。

小練習：請選出錯誤的地方，並予改正。（留言作答）
1. We strongly suggest that Smith is told about his physical condition as soon as possible. (研究所考試英語試題, 82 A)
2. The lawyer asked that the case is postponed for one month. (TOEFL, 79. 5 – 8)