1) 分辨的标志，凡是“但是”的意思，however 总是单独出现，后面一定要有逗号，读时有停顿，如果放在句中，则前面也有逗号。

• That is one reason why their economic policies are unlikely to restore full employment. It is not, however, the only one.这是他们的经济政策为什么不大可能恢复充分就业的一个原因。

但这并不是唯一的原因。如果 however 所在的句子是并列句的第二分句，它前面应该有分号 (；)。

• I wanted to study; however, I was too tired.我想学习，但我太累了。

3) 而凡是“无论多么”的意思，however 就不能“独来独往”，后面不能有逗号，后面必须有形容词或副词，或是后面接着有一个从句（但从句中的谓语动词 to be 有时可以省略）。

• The important point is that, however the recording is done, the playback is high fidelity.重要的一点是：无论用哪种方法来录音，播放总是高保真的。
• However relations with America and the region go, Mr Koizumi would be wise to consider another comparison with Mr Blair. (The Economist, May 3, 2003, p.42)无论同美国和本地区的关系搞得如何，小泉先生最好还是考虑一下从另一个方面同布莱尔先生相比较，方属明智。
• However Pluto is classified, it is an object on the edge of the immediate solar system that scientists want to study up close.无论冥王星分到哪一类，它都是科学家们想近距离考察的太阳系边缘物体。

要注意，如果 however 从句中有“无论”所指的形容词或副词，都要提前放在 however 后面。

• …however successful he is on the international stage...…无论他在国际舞台上多么成功…
• She could not remember, however hard she tried, the first time they had met.她无论怎样努力回忆，都想不起来他们第一次是怎样见面的。
• However strong the temptation, don't stay in any job too long.无论诱惑力多么强，干任何工作都不要呆得太久（省略谓语动词 to be）。
• She loved flying. It always gave her a thrill, however many times she'd done it.她喜欢飞行。不管她已经坐过多少次飞机，但她每次飞行总是感到一种兴奋刺激。
• Almost no money was available for the development of weapons of mass destruction, however much he might have wished to rebuild his arsenal.无论他多么希望重建自己的武库，他也几乎没有什么钱来开发大规模毁灭性武器。

however 是副词（“但是”）还是连词（“无论多么”），从上面的分析看来，本来是容易辨别的，但是实际上往往不但中国人容易看错，而且外国人也容易看错。例如 Jane Austen 的著名小说《傲慢与偏见》(Pride and Prejudice) 一开头第二段：

• However little known the feelings or views of such a man may be on his first entering a neighbourhood, this truth is so well fixed in the minds of the surrounding families that...(p.1)

这里的 however 后面没有逗号，而是紧接一个形容词成分 little known，可见它应该是个连词（“无论多么”），而且从 however 直到 neighbourhood 并不构成一个独立句，而只是一个让步从句。但是该书至少有两个西班牙文译本都同样把它误认为副词（“但是”）。这一来，后面的 this truth（本来指前一段的内容）就被错误地当作另一句的开始，用来指 however 后面的内容了。

4) 但是 however 也可以作为句子中一个较为复杂的名词成分内部一个修饰定语的状语，此时 however 不是引入让步状语从句，而只是一个副词，但是这个副词不是以“但是”的意义修饰全句，而是以“无论多么”的让步意义仅仅修饰句中的一个形容词。而且要注意，此时“however + 形容词”要放在“a + 名词”之前。

• Traveling on however humble a scale is expensive in Scotland.无论规格多么简朴，在苏格兰旅行总是昂贵的。

1) 如果前面用了 although/though 从句，主从句之间用逗号分开，however 可以就在逗号后面，再加逗号，然后是主句；或者 however 可以插在主句当中，前后逗号。

• Although this month seemed to be a very quiet month, however, there were a number of activities that had far reaching consequences. 或 Although this month seemed to be a very quiet month, there were, however, a number of activities that had far reaching consequences.虽然这一个月份看来十分宁静，但是也有过一些结果深远的活动。

2) 如果前面不用 although/though，原来的原因从句就变成了独立句，此时它同后一句之间要用分号 (；) 隔开。后一句的 however，也是既可以放在句首，后加逗号，也可以插在句子当中，前后逗号。例如：

• This month seemed to be a very quiet month; however, there were a number of activities that had far reaching consequences. 或
  This month seemed to be a very quiet month; there were, however, a number of activities that had far reaching consequences.

3) 如果干脆不用 however 而用 but，则两个句子成了一个并列句的两个分句，彼此之间不用分号隔开，而用逗号（但是用分号也可以）：

• This month seemed to be a very quiet month, but there were a number of activities that had far reaching consequences.