1.当表示“相似”时，多用as，避免使用that。
She has the same fair hair and blue eyes as her mother had.
她和母亲一样有着同样的金色头发和蓝色眼睛。（as做had的宾语）
This coffee is the same as we had at Mrs.Dawson’s.
这咖啡和我们在道森妇人家喝的一样。
His hair’s the same colour as her mother’s.
她的头发和母亲的头发是同样的颜色。（mother’s后面省略了is，所用as作表语）
2.当表示“同一”时，多用that，但也可以用as。
He works in the same shop（that/as）I do.
他和我在同一家商店工作。（as/that作宾语）
I went out the same way（that）I’d got in.
我顺着进来的原路出去的。（that作状语，表方式）
We rode the same way as we had come out the evening before.
我们乘车行驶在前一天晚上出来的同一条路上。（as作状语，表方式）
（4）Meet me at the same place as you did yesterday.
请到昨天见我的那个地方来见我。（as作地点状语）
3.定语从句为省略结构，要用as不用that。
I read the same book as you.
我和你读的书是一样的。（as表示相似）
He gave the same answer as before.
他给的答案和以前的相同。（as表示同一）
She lives in the same house as her husband.
她和丈夫住在一个房子里。（as表示同一）
4.the same后没有被修饰的名词也没有暗含一个one时，只能用as而不用that。
I feel the same today as I did yesterday.（today在这里是副词作状语）
5.that作宾语可以省略而as不可以。
She is the same girl that I sat next to last year.
她和去年坐在我旁边的那个女孩是同一个人。
I live in the same house as he lives in.
我和他住在同一个屋。