so far 表示until this time or to this place；时间点或地点，后面的句子一般用完成时，而且so far后面一般接比较贬义或者消极的信息。比如 So far no further news had been obtained．至今没有得到进一步的消息 by now 也是表示到目前为止，但是后面没有要加消极信息的那一层意思，也没有严格的时间点或地点的要求，如 By now he has won the first. 目前他已经得了第一。。。希望能帮到你。。。
第2个回答 2012-05-26
by now 表示“现在，这时，至此”的意思 I hope you have understood me by now.我希望到现在你该理解我了。 so far 意为“迄今为止”，常与完成时态连用 Do we know anything so far that we can point to that would give us a departure? 目前为止我们能在我们了解到的,东西中找出一些违背这些规律的例子吗？
第3个回答 2012-05-24
There really is no difference but you can say that by now is saying "they should be here by now" . And so far is saying "I have $10 so far".