为了让考研的同学更高效地复习考研英语，新东方在线考研频道整理了2025考研英语语法备考句子扩展：成分替换，考研的同学可以了解一下，希望对大家有所帮助。
句子扩展：成分替换
句子的复杂不仅体现在修饰成分繁多上，还体现在句子成分本身的复杂化上，下面就过句子成分由简单到复杂的替换来演示句子是如何变难的。
(一)钻石句型①主谓宾句型
主语扩展：
The event amazed the world.
What happened on that day amazed the world.
To hold the Winter Olympics in China amazes the world.
Holding the Winter Olympics in China amazed the world.
That China is to hold the Winter Olympics amazes the world.
注：由此可见，充当主语的除了简单的名词(短语)、代词、数词，还可以是形式比较复杂的动词不定式(短语)、动名词(短语)、主语从句。考研翻译中明确这一点，才能打开思路，更好地划分句子成分，从而做到真正理解句意，进而很好的用汉语表达出来。
宾语扩展：
He can hear me.
He can hear the strange sound.
He can hear anything happening in the building.
He can hear the sound from that building.
He can hear a girl crying in the building.
He can hear whatever happens in the building.
He decided to check what’s going on in the building.
He considered going to the building for a look.
注：由此可见，充当宾语的除了简单的名词(短语)、代词、数词，还有形式比较复杂的动词不定式(短语)，动名词(短语)，宾语从句。同样的，考研翻译中明确这一点也非常重要，有助于打开思路，理清句子成分。
(二)钻石句型②主系表句型
主语扩展：钻石句型①中的主语扩展(成分替换)已经很明确了，此处不再重复。
表语扩展：
They are beautiful.
They are in the zoo.
They are beautiful animals in the zoo.
They are interested in the new invention.
To see is to believe.
That is what we are talking about.
注：由此可见，充当表语的成分繁多，有形容词(短语)，介词短语，动词不定式(短语)，分词(短语)，名词，表语从句。在考研翻译，中若这些充当表语的成分变得更长一些，要注意识别。
三、示例
过下面这个例子，并结合以上句子的扩展，体验一下英文句子的各个成分及结构。
But science does provide us with the best available guide to the future, and it is critical that our nation and the world base important policies on the best judgments that science can provide concerning the future consequences of present actions.
解析：
并列句。第一个分句主干：science does provide us。其中with the best available guide to the future为状语修饰provide，the best available和to the future分别为guide的前置定语和后置定语，由此本句宾语被复杂化 第二个分句主干：it is critical that...,其中，it为形式主语，that从句为真正的主语，从句主语为名词短语our nation and the world, base...on...为固定搭配，第二个that从句为judgments的定语从句，分词结构concerning...为judgments的后置定语。
以上是新东方在线考研频道为考生整理的“2025考研英语语法备考句子扩展：成分替换”相关内容，希望对大家有帮助，新东方在线考研频道小编预祝大家都能取得好成绩!更多英语复习相关信息尽在新东方在线考研英语频道。