although

though, although, as, even though

这些连词均可表示“虽然，尽管”之意。
though: 和although在意义上几乎毫无区别，但在习惯用法上这两个词仍有以下一些差异：1.though可引出倒装语序的让步状语从句，although 则不能。2.though可与even连用，although则不能；在as though结构中，只用though，不能用although。3.though可以置于从句末，而although则不能。4.引出省略句时，通常用though。
although: 与though在意义上相似，但文体上是比较正式用词，语气比though强。
as: 引出让步状语从句只用于倒装语序结构中，语气强于上述两个连词。
even though: （＝even if），意为“即使”，引导让步状语从句。though也引导让步状语从句，意为“虽然”；even though有退一步设想的意味，与though不同。though引导的句子所说的是事实，even though引导的句子所说的则不一定是事实。例如：

• he will not tell the secret even though（even if）he knows it．
  即使他知道这个秘密，他也不肯说出来。
• he will not tell the secret though he knows it．
  他虽然知道这个秘密，但他不会说出来。

1. A car overtook me although I was going fast.
   我虽然开得很快，还是被一辆车超过了。
2. Although she was poor, she was living in genteel poverty.
   尽管她贫穷，但她总想装出上流社会阶层的样子。
3. Although they can swim, the polar bears are terrestrial animals.
   北极熊虽然会游泳，但也是陆栖动物。
4. She seemed a babe although she was already thirty.
   尽管她已经三十岁了，看上去还象个小孩。
5. Although my uncle is old, he looks very strong and healthy.
   我的叔叔虽然老了，但他看上去还是很健壮。