so的詞序為：so+ adj. + a（an） + n.such的詞序為：such +a（an） +adj. + n. so nice a coat =such a nice coat 這麼漂亮的一件外套
so interesting a book = such an interesting book 那麼有趣的一本書
後面接複數名詞或不可數名詞時，只能用such，而不能用so.如：
such beautiful flowers 這麼美麗的花
such clever children 如此聰明的孩子
但是，複數名詞或不可數名詞前有many，few，much，little修飾時，只能用so而不能用such，這是一種固定用法。如：so many books 這麼多書,so few people 這麼少的人,so much money 那麼多的錢so little milk 那麼少的牛奶
2. 和“that”連用時，意思基本一樣，但句型結構不同。“so…that…”句型結構為：
so + adj. （adv.） +that…
so + adj. +a（an）+單數n. +that…
so +many（few）+複數n. +that…
so +much（little）+不可數n. +that…如：
This book is so interesting that I have read it three times. 這本書如此有趣，我已經看了三遍。
He spoke so fast that we couldn‘t understand him. 他說得太快，我們都未能聽懂他的話。
It was so hot a day that nobody wanted to do anything. 天氣很熱，誰都不想幹活。
There were so many people that we could hardly move on. 這麼多人，我們簡直無法繼續往前走。
“such…that…”句型結構為：
such + a （an）+adj. +單數n. +that…
such + adj. +複數n. +that…
such +adj. +不可數n. +that…
She is such a pretty girl that everyone likes her. 她是個很可愛的小姑娘，大家都喜歡她。
They are such delicious cakes that I want to eat another two. 這麼可口的蛋糕，我還想再吃兩塊。
It is such sweet milk that we all want to drink it. 這麼香的牛奶，我們都想喝。
補給站：由於so 和such後跟單數可數名詞時，可以換用，同樣“so…that…”與“such…that…”也可以進行同義句改寫。如上文中：This book is so interesting that I have read it three times. 可改寫成：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. 可改寫成：It was such a hot day that nobody wanted to do anything.
so與such都有“如此、這麼、那麼”的意思，可進行同義改寫，但用法不同。
1. so是副詞，修飾形容詞和副詞；而such是形容詞，修飾名詞。它們後面接單數可數名詞時，詞序不同。
so的詞序為：so+ adj. + a（an） + n.such的詞序為：such +a（an） +adj. + n. so nice a coat =such a nice coat 這麼漂亮的一件外套
so interesting a book = such an interesting book 那麼有趣的一本書
後面接複數名詞或不可數名詞時，只能用such，而不能用so.如：
such beautiful flowers 這麼美麗的花
such clever children 如此聰明的孩子
但是，複數名詞或不可數名詞前有many，few，much，little修飾時，只能用so而不能用such，這是一種固定用法。如：so many books 這麼多書,so few people 這麼少的人,so much money 那麼多的錢so little milk 那麼少的牛奶
2. 和“that”連用時，意思基本一樣，但句型結構不同。“so…that…”句型結構為：
so + adj. （adv.） +that…
so + adj. +a（an）+單數n. +that…
so +many（few）+複數n. +that…
so +much（little）+不可數n. +that…如：
This book is so interesting that I have read it three times. 這本書如此有趣，我已經看了三遍。
He spoke so fast that we couldn‘t understand him. 他說得太快，我們都未能聽懂他的話。
It was so hot a day that nobody wanted to do anything. 天氣很熱，誰都不想幹活。
There were so many people that we could hardly move on. 這麼多人，我們簡直無法繼續往前走。
“such…that…”句型結構為：
such + a （an）+adj. +單數n. +that…
such + adj. +複數n. +that…
such +adj. +不可數n. +that…
She is such a pretty girl that everyone likes her. 她是個很可愛的小姑娘，大家都喜歡她。
They are such delicious cakes that I want to eat another two. 這麼可口的蛋糕，我還想再吃兩塊。
It is such sweet milk that we all want to drink it. 這麼香的牛奶，我們都想喝。
補給站：由於so 和such後跟單數可數名詞時，可以換用，同樣“so…that…”與“such…that…”也可以進行同義句改寫。如上文中：This book is so interesting that I have read it three times. 可改寫成：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. 可改寫成：It was such a hot day that nobody wanted to do anything.
3. so與that可以直接構成片語“so that”，引導目的和結果狀語從句，表示“以便、以致”的意思。如：
He worked hard so that he could pass the exams. 為了能透過考試，他學習很認真。（但such沒有這種用法）