Section_ⅢGrammar - 主语和动词

　　语法图解

　　探究发现

　　①Antarctica is the coldest place on Earth.

　　②They call it Anti­Arktikos, or Antarctica ...

　　③98% of the surface is covered permanently in the ice cap.

　　④To learn a foreign language well is not easy.

　　⑤Swimming is a good exercise.

　　⑥Whether he will come is doubtful.

　　⑦It is difficult to imagine a more inhospitable place.

　　⑧I hope to see you soon.

　　⑨He came in and sat down.

　　⑩The student went pale when he saw the teacher.

　　⑪I can easily tell my father's step.

　　⑫We hadn't walked far when we lost our way.

　　[我的发现]

　　(1)①～⑥句中的黑体部分在句中均作主语。

　　(2)由④⑤⑥句可知，不定式、动词­ing形式、从句作主语时谓语动词通常要用单数形式。

　　(3)⑦句中用it作形式主语。

(4)⑧～⑫句中，黑体部分均为动词，且⑧⑨句中的动词可直接作谓语，而⑩⑪⑫句