复句和分句
Complex sentences and clauses

第六级你说过“因为堵车，所以我迟到了”，也说过“虽然很累，但是他还是来了”。你当时觉得奇怪：英语只用一个 because，汉语为什么两头都要说？现在可以回答了——因为汉语的分句没有形状上的记号，全靠这一对词告诉你两半是什么关系。

In level 6 you said 因为堵车，所以我迟到了 and 虽然很累，但是他还是来了, and it probably felt odd: English uses one 'because', so why does Chinese mark both ends? Here is the answer — a Chinese clause has no shape of its own, so the pair of connectives is the only thing telling you how the two halves are related.

分句本来都能单说：“堵车了。”“我迟到了。”把它们放在一起，中间停一下，就成了一个复句。复句说的仍旧是一件事，只是这件事有两个面。第二课说过，单句只有一个主谓结构做架子；复句是好几个摆在一条线上。

Each clause could stand alone: 堵车了. 我迟到了. Put them side by side with a pause and you have a complex sentence. It still reports one situation, only a situation with two sides. Lesson 2 said a simple sentence has one subject-predicate frame; a complex sentence lines several of them up.

英语说 because A, B，只用一个词，因为它的从句自己有形状。汉语的分句跟单句长得一模一样，看不出谁主谁次，所以要在两个分句的头上各放一个词：前一个提起，后一个接住。位置也固定——关联词语站在自己那个分句的最前边，不能跑到另一个分句里去。

English writes 'because A, B' with one word, because its subordinate clause has a shape of its own. Chinese clauses look exactly like simple sentences, so nothing shows which outranks which — hence one word at the head of each: the first raises the relation, the second catches it. Their position is fixed too: a connective stands at the front of its own clause and never wanders into the other one.

主语不同，两个都要说：因为他没来，所以我们等了半天。主语相同，第二个分句直接从动词说起：他吃了饭就走了。这个“了”说的是先后，不是过去——“明天我吃了饭就去”也是这个说法。还有一条老规矩：主语相同的时候，关联词语放在主语后边（他虽然很累，但是还是来了）；主语不同的时候，放在主语前边（虽然他很累，但是我们还得走）。

When the subjects differ, both are said: 因为他没来，所以我们等了半天. When they are the same, the second clause starts straight from the verb: 他吃了饭就走了. That 了 marks sequence, not pastness — 明天我吃了饭就去 works the same way. One more old rule: with a shared subject the connective follows it (他虽然很累，但是还是来了); with different subjects it comes first (虽然他很累，但是我们还得走).

并列复句常用的关联词语有“又…又…、一边…一边…、也…也…、不是…而是…”。别的关系——原因、转折、条件、假设——两个分句就有主有次，前后不能随便换。那几种下一课细讲。

The coordinate connectives are 又…又…, 一边…一边…, 也…也…, 不是…而是…. In every other relation — cause, contrast, condition, supposition — one clause outranks the other and their order is fixed. The next lesson takes those up in detail.