在英语学习中，很多同学都容易混淆 so与 such的用法，认为它们没什么区别！但其实不然，虽然 so与 such都有“如此、这么、那么”的意思，可进行同义改写，但其具体用法还是存在差异。

1. so是副词，修饰形容词和副词；而 such是形容词，修饰名词。它们后面接单数可数名词时，词序不同。

so的词序为： so+ adj.+ a/ an+ n.

such的词序为： such+ a/ an+ adj.+ n.

它们可以表达同样的意思，因此它们可以进行同义改写。

so nice a coat= such a nice coat这么漂亮的一件外套

so interesting a book= such an interesting book那么有趣的一本书

补给站：后面接复数名词或不可数名词时，只能用 such，而不能用 so，如：

such beautiful flowers这么美丽的花

such clever children如此聪明的孩子

但是，复数名词或不可数名词前有 many/ few/ much/ little等修饰时，只能用 so而不能用 such，这是一种固定用法。如：

so many books这么多书

so few people这么少的人

so much money那么多的钱

so little milk那么少的牛奶

2.和“ that”连用时，意思基本一样，但句型结构不同。“ so… that…”句型结构为：

so+ adj.( adv.)+ that…

so+ adj.+ a/ an+单数 n.+ that…

so+ many/ few+复数 n.+ that…

so+ much/ little+不可数 n.+ that…

This book is so interesting that I have read it three times. 这本书如此有趣，我已经看了三遍。

He spoke so fast that we couldn&# 39; t understand him. 他说得太快，我们都未能听懂他的话。

It was so hot a day that nobody wanted to do anything. 天气很热，谁都不想干活。

There were so many people that we could hardly move on. 这么多人，我们简直无法继续往前走。

“ such… that…”句型结构为：

such+ a/ an+ adj.+单数 n.+ that…

such+ adj.+复数 n.+ that…

such+ adj.+不可数 n.+ that…

She is such a pretty girl that everyone likes her. 她是个很可爱的小姑娘，大家都喜欢她。

They are such delicious cakes that I want to eat another two. 这么可口的蛋糕，我还想再吃两块。

It is such sweet milk that we all want to drink it. 这么香的牛奶，我们都想喝。

补给站：由于 so和 such后跟单数可数名词时，可以换用，同样“ so… that…”与“ such… that…”也可以进行同义句改写。如上文中：

This book is so interesting that I have read it three times. 可改写成： This is such an interesting book that I have read it three times.

It was so hot a day that nobody wanted to do anything. 可改写成： It was such a hot day that nobody wanted to do anything.

3. so与 that可以直接构成词组“ so that”，引导目的和结果状语从句，表示“以便、以致”的意思。如：

He worked hard so that he could pass the exams. 为了能通过考试，他学习很认真。（但 such没有这种用法）