However是一个常用的副词，表示“然而”，用于连接两个相对矛盾的句子或观点，起到转折或对比的作用。在句子中，however通常出现在两个句子之间，用逗号隔开。例如：

- I was planning to go to the beach today, however, it is raining heavily.

- John is a hardworking student, however, he didn't do well in his final exams.

除了单独使用之外，however还可以与其他单词组成短语，用于表达更加复杂的意思。以下是一些常见的however短语：

1. However much/ Many/ Few/ Little/ Often/ Seldom/ etc. - 表示不管多少、多少、少量、少许、经常、很少等等。例如：

- However much I try, I can't seem to understand this math problem.

- However little time we have left, we need to finish this project on time.

2. However much/ Many/ Few/ Little/ etc. + Noun - 表示数量的限制。例如：

- However many books she reads, she never seems to get tired of reading.

- However little money we have, we need to find a way to make it work.

3. However + Adjective - 表示程度的限制。例如：

- However difficult the task may seem, we need to try our best to complete it.

- However boring the movie was, I still stayed until the end.

4. However + Adverb - 表示程度的限制。例如：

- However fast he runs, he can never catch up with me.

- However carefully you drive, accidents can still happen.

总之，however是一个常用的转折副词，可以用于连接两个相对矛盾的句子或观点。同时，它还可以与其他单词组成短语，表达更加复杂的意思。