于是 and 所以

bodawei

January 07, 2011, 10:17 AM

Oh GOOD question. It seems that they are highly interchangeable and it is hard to pick differences from examples in the Glossary or in the 现代汉语词典.  You see 所以 at the beginning of sentences, and even on its own, still acting as a conjunction.  It also commonly pairs with 因为 and I don't know whether 于是 does. 

I will watch out here for the answer and hopefully learn.

zhenlijiang

January 07, 2011, 11:02 AM

In lieu of attempting an explanation (I began, but it started getting muddlier and muddlier) here's my attempt at the exercises--1) 所以 2) 于是 3) 于是 4) 所以  5) 所以.

Does your book give the correct answers? If I'm wrong I'll also wait for someone else who knows to come to the rescue! If I'm right I'll try to pick up the explanation later. But always, a knowledgeable person's input is more welcome. 

Oh and what explanation does your book give?

tingyun

January 07, 2011, 05:07 PM

于是 shows a contination kind of relationship between the sentences, sometimes this has a bit of cause and effect mixed in, but the stress is on the continuation (usually).  Its often the right choice for narrating someone's actions, or developments. 

所以 shows a cause and effect relationship between the sentences, and as bodawei notes often pairs with 因为 (于是 does not pair with 因为).  Its often the right choice for explaining the origin or cause of things.

With this is mind, I'd agree with Zhenlijiang and say 2 and 3 are 于是, 4 is 所以.  However, I think 1 and 5 could be either - I think your book is really trying to draw a hard distinction where there is none.  Despite 于是's focus on continuation, it does have some causal meaning to it - and you can find writings where it clearly is being used as a cause and effect term.  And anyway, 1 and 5 have a little of both operating.  I'm sure you could get some native speakers to swear to you it should be one or the other, but its like getting someone to edit your paper and having 'therefore...' changed to 'from this...'.  In the same way you can get people to explain to you differences between 然后，而后，尔后...and of course they exist (in formality, in emphasis, in extent to which they have causality or nessecity relationships halfway implied, in places where they seem natural to choose) - but there will still remain much crossover.

So the common use is as in the above examples - in the 2nd sentence used as a connector.  于是 is limited to this role, However, 所以 is broader.  It can be used as a noun meaning 'cause' in formal writing - ie 不明所以 (do not know the reason why), and it can also be used to show the same cause and effect meaning with the sentence ordered backwards - ie 他之所以Effect (the fact about him that you are about the explain the reason of)，是因为Cause.

Tangent on Origins of these terms (may or may not be useful depending on your level of interest)

Also, in getting a sense of use, it may be helpful to understand the origin of these terms.  所以 - 以 here is 'use' , 所 is in its standard use of changing a verb into a noun (ie 学 is verb to study, 所学 is noun 'that which you study or studied', ie a noun that might be math, or science, or cooking, or whatever; 写 is verb to write, 所写 is noun, 'that which you wrote', ie it might be an essay, a book, a note).  so 所以 is a noun meaning 'that which was used'.  It originated in this meaning, so if you told me that you just wrote a book, and I asked about 所以, you could reply telling me 'your pen', or of the knowledge you used, etc.  Actually, it never technically lost this meaning, though it would have to be very, very formal modern writing to use 所以 in the concrete sense - otherwise you won't see that.  It very soon got an extention to its meaning by analogy - ie, it became a noun meaning 'cause', as cause is what the natural world or universe 'uses' to achieve the effect (you can see this in other words too, ie 何以 (何 is a question word meaning 'what), technically means 'what is used', but is almost only seen in an abstract extened meaning of 'why', 'how').

Now, 于是 can be understood by a similar analysis, 于 means something like 'at', or 'among', 是 means 这 (是 was not a 'to be' verb originaly, just a pronoun), so together 于是 means something like 'at this' （actually there used to be a varient 于时， and this temporal sense still informs the meaning）.  However, complicating matters is the fact that 于是 could also be viewed as 'through this', and it also could be used in a very direct causal sense, as 是 was often used this way  -  是以 is a very formal word for thereofore (it in a more natural order would be 以是 - 'using this' in the same abstract extentsion of the natural world using something as cause - but classical chinese often inverts word order, actually the 何以 I menotioned above is another such inversion, as the reverse order would be more grammatically natural - but both of these 'natural orders' would be incorrect, the inversion is mandatory).  So 于是 could also be viewed as 'from this' or some such, and in classical chinese often had a very causal meaning.  While this aspect faded a bit in modern language, it still retains some of that sense, and as in much of chinese, the flexibility of the classical language means that, if you are reading very formal modern writing, its potential to deviate from the commonly encountered modern somewhat narrowed use increases...

班廷筠