so far as ，as far as，so long as，as long as之间的区别

so long as 1 只要 既然
He need not step down so long as they support him.
只要他们支持他，他就不必辞职．
2 由于
as far as＝so far as 1 到...那么远
例:The children walked as far as the lake.孩子们一直走到湖边
2 （表示程度 范围）就．．．；尽．．．；至于
例：as far as I know 就我所知
as far as possible 尽可能
（我已尽力了 希望对你有用）

so far as有到。。。。为止的意思。
so far as与as far as也都有与。。。一样远！
as long as和so long as都有和。。。。一样长的意思。
除此之外as long as 还有只要的意思！

as long as:与....一样长
so far as:直到....
as far as: 与....一样远
so long as :直到....