这两个词其实都是所谓的 conjunctive adverb, 即 起连接作用的副词（可以把它们归类为副词，也可以把它们归类为连词）。
这两个词连接的前后两部分都存在转折关系，都可以翻译为“然而，不过”。但是 nevetheless 比 however 更正式，强调更重。
nevertheless 可以用在句尾，however 不可以。
eg:
1. I was dying to eat these dishes. However, I am not satisfied.
2. I will do my best. Nevertheless, I can't promise you I will definitely succeed.
3. The result is not satisfying; nevertheless, we have to face it.
4. Our defeat was expected but it is disappointing nevertheless.
5. He should have good reasons to believe that his solution is correct. Nevertheless, errors are always possible, especially if the argument is long and involved.