1 主語
可以充當主語的詞：
- 名詞、代詞
- doing
- to do (可放句首或者句尾)
1.1 【例子】【翻譯】如今，在中國乘坐地鐵正變得越來越方便。
Nowadays, taking the subway in china is becoming more and more convenient.
- 表示一類事物，可用the,a,或者複數：
- taking the subway
- taking a subway
- taking subways
- 使用to do：
Nowadays, to take the subway in china is becoming more and more convenient.
或者：
Nowadays, it is becoming increasingly convenient to take the subway in china .
1.2 【例子】【translation】過去，乘飛機對大多數中國人來說是難以想像的。
In the past, taking a plane to travel was unimaginable for most Chinese people.
In the past, travelling by plane was unimaginable for most Chinese people.
In the past, to travel by plane was unimaginable for most Chinese people.
In the past, it was unimaginable for most Chinese people to travel by plane.
In the past, it was beyond imagination for most Chinese people to travel by plane.
1.3 【閱讀】Printing with moveable type on paper dramatically reduced the cost of producing a book compared with the old-fashioned ones handwritten on vellum, which comes from sheepskin.
dramatical 劇烈的，顯著的。
dramatically 劇烈地，顯著地。
vellum 牛皮紙
sheepskin 羊皮，羊皮紙
Printing … reduced the cost …
2 四級語法
如何描述一件事？
那就是簡單句。
如何描述多件事？
長難句。