however和nevertheless有什么区别？

NHK : 大多数的情况下...however 和 nevertheless / nonetheless 是可以互相交换使用的...意思是说...可以完全取代对方...但是...它们在文法上...仍然有1点点的差别...nevertheless 会应用在...跟前文不协调的时候...就是英文常说的 however = but...而 however 是除了前文以外...仍然会涉及1些前文没有提到的原因...所以...同1句句子...在某情况下...会用 however 或 nevertheless...是有稍稍不同的意思...或许换个角度说...nevertheless = in spite of...而 however = in spite of + on the other hand...还有1个特别的用法...就是比较起前文的时候...nevertheless / nonetheless 会带有1点惊讶的意味...但 However 就没有..."Nevertheless" tells you that the following information is surprising in view of the previous information..."However" does not have this connotation of unexpectedness...for example..."Japanese is a very difficult language. Nonetheless she spoke it quite fluently after only 6 months in Tokyo."...in this example..."However" can be adapted too.....BUT....."Japanese is a very difficult language. However we can drop it in the second year."...Nonetheless / Nevertheless cannot be adpated to replace "However" in the second example as there is no surprising information..........