however
/haʊˈevə(r)/adverb
1
- used to introduce a statement that contrasts with or seems to contradict something that has been said previously然而, 可是, 不过：
People tend to put on weight in middle age. However, gaining weight is not inevitable.
人们往往会在中年体重增加。然而, 这并非不可避免。
2
- relative adverb in whatever way; regardless of how不管用什么方式; 不管怎么, 无论如何：
however you look at it, you can't criticize that.
不管你怎么看这件事, 你都不能批评那一点。
2.1
- with adj. or adv. to whatever extent不管多么：
he was hesitant to take the risk, however small.
他不情愿冒风险, 不管多小。
USAGE
When ever is used for emphasis after how or why, it should be written as a separate word. Thus it is correct to write how ever did you manage? rather than however did you manage? （as distinct from other uses of the adverb however, which is always written as one word）. However, with other words such as what, where, and who, the situation is not clear-cut: both two-word and one-word forms （both what ever and whatever, and so on） are well represented, and neither is regarded as particularly more correct than the other.