高中英語語法 主語從句
1． 定義：用作主語的從句叫做主語從句。
2． 構成：關聯詞+簡單句
3． 引導主語從句的關聯詞有三類：
(1) 從屬連詞that。 如：That they were in truth sisters was clear from the facial resemblance between them.
很明顯，她們確是親姐妹，她們的臉型很相似。
(2) 從屬連詞whether。如：
Whether hell come here isnt clear. 他是否會來這裡還不清楚。
(3) 連線代詞who, whom, whose, what, which, whoever, whatever, whichever
連線副詞 where, when, how, why。如：
What she did is not yet known. 她幹了什麼尚不清楚。
How this happened is not clear to anyone. 這事怎樣發生的，誰也不清楚。
Whoever comes is welcome. 不論誰來都歡迎。
Wherever you are is my home ---- my only home. 你所在的`任何地方就是我的家----我唯一的家。
解釋：
1． 主語從句能用it作形式上的主語。常以it作形式主語的句型有：
A. It+be+形容詞(obvious, true, natural, surprising, good, wonderful, funny, possible, likely, certain, probable, etc.)+that從句。如：
It is certain that she will do well in her exam. 毫無疑問她考試成績會很好。
