因果、转折、条件复句
Cause, contrast, condition

第六级里你已经说过这样的句子：“因为下雨，所以我们没去。”“虽然很累，但是他还在工作。”“只要你来，我就等你。”“如果明天不下雨，我们就去公园。”那时候你是照着说的；现在给这四种关系起名字——因果、转折、条件、假设。四种复句，四对关联词语。

You have been saying these since level 6: 因为下雨，所以我们没去; 虽然很累，但是他还在工作; 只要你来，我就等你; 如果明天不下雨，我们就去公园. You said them by pattern. This lesson names the four relations — cause, contrast, condition, supposition — and shows you the pair of connectives that carries each one.

关联词语常常成对出现：前一个分句用“因为”，后一个分句就用“所以”。英语里两个只能留一个，汉语两个都留最自然。原因也可以放在后面：“我们没去，因为下雨了。”这样听起来像是补充说明，不像正式的书面语。

The connectives come in pairs, and Chinese keeps both — 'because … so …' is a mistake in English but the normal shape in Chinese. You may also put the cause second, 我们没去，因为下雨了, which sounds like an afterthought rather than written prose.

“但是”“可是”“不过”都表示转折，语气一个比一个轻，“不过”最软，多用在口语里。“虽然”可以换成“尽管”，后面常跟“还是”：“尽管很难，他还是做完了。”前一个分句让一步，后一个分句才是要说的话。

但是, 可是 and 不过 all mark the turn, in falling order of force — 不过 is the softest and belongs to speech. 虽然 can be swapped for 尽管, which likes 还是 behind it: 尽管很难，他还是做完了. The first clause concedes; the second one is the message.

后一个分句里的“就”“才”“都”是副词，位置在主语后面、动词前面，不能放到句子最前头：说“我就等你”，不说“就我等你”。“就”表示条件够了，事情容易；“才”表示条件不够就不行，语气紧。口语里“无论”常说成“不管”。

就, 才 and 都 in the second clause are adverbs, so they stand after the subject and before the verb — 我就等你, never 就我等你. 就 says the condition is easily met; 才 says nothing happens without it. In speech 无论 is usually 不管.

“要是”比“如果”口语一些，后面还可以加“的话”：“明天下雨的话，我就不去了。”说话的时候，前面那个关联词常常省掉，只留后面的“就”“也”“都”：“你不来，我也去。”“下雨了，我们就不去了。”意思一点儿不少，句子短了一半。前后两个词一般不同时省——留一个，关系才看得出来。

要是 is the spoken 如果, and it can take 的话 after the clause. In speech the first connective is the one that goes: 你不来，我也去 and 下雨了，我们就不去了 say everything, at half the length. What you may not drop is both — one of the pair has to survive, or the relation disappears.