as...as；not so. . .as

张文

as...as；not so. . .as或not as...as 1)表示"相等"用as...as。
2)表示"不相等"用not so...as或not as...as。如：
1)This knife is as sharp as that one.这把刀跟那把一样快。 Bill is as tall as I. 比尔和我一般高。
Is this bag of soyabeans as heavy as that one?这袋大豆跟那袋一样重吗?
You know as well as I do.你和我一样明白。
[注]注意as后面的形容词如作定语，而被定语修饰的名词有不定冠词a时，冠词a须放在形容词之后，如German is as difficult a language as English.(德语和英语一样难学。)。这样的词序也适用于so，如I have never seen so beautiful a place as Guilin before.(我过去从未见过像桂林这样美丽的地方。)
2)tian An Men Square was not so big as it is now.天安门广场过去没有现在这样大。
The Atlantic Ocean is not as big as the Pacific ocean.大西洋没有太平洋大。

张文

表示"几倍于"
用twice (两倍)，three times(三倍)等加as...as.. 如：
New York is ten times as big as my home town.纽约有我的家乡十个大。 The output of the paper mill is now three times as high as it was in 1966.这家纸厂的生产比一九六六年增加两倍。
This river is twice as long as that one.这条河比那条河长一倍。 Asia is four times as large as Europe.亚洲比欧洲大三倍。