(一)主要成分
1. 主语
主语是动作发出者。一般由名词、代词、数词、不定式、动名词、从句或名词化形容词等充当。一般位于句首, 而在there be句型和倒装句中, 主语常位于be动词、助动词、谓语动词或情态动词之后。若不定式短语作主语, 常用it作形式主语, 则把真正的主语(不定式短语)放在句后。
※(2020·全国Ⅲ卷)It’s hard to tell exactly how many people agree with him, but research indicates that the numbers have been rising for some time.
很难说到底有多少人同意他的观点, 但研究表明, 这一数字已经上升了一段时间。
【小题快练】 单句语法填空
①(2020·江苏高考)I was in the middle of the Amazon (亚马逊) with my wife, who was there as a medical researcher.
②(2018·浙江高考)They realize how cheap it can be to eat out.