but 口语常用词，语气较强，泛指与前述情况相反。
however 表转折关系，语气稍弱于but，连接性也弱一些，因而常作插入语。
still 语气强，多用于肯定句或疑问句。指尽管作出让步，采取措施或表示反对，但情况仍然如故，无所改变。
yet 常用于否定句，语气比still稍强。指不管作出多大努力或让步，仍达不到预期的结果。
nevertheless 指尽管作出完全让步，也不会发生任何影响。
while 表对比，一般可与whereas换用，但程度弱一些。
whereas 表对比，一般可与while互换。
参考例句
1. Back to hostel yet? To eat yet? 回到宿舍了没有？吃饭了没有？
2. The feminism age has yet to come. 女权主义的时代还没有到来。
3. Yet, all this work was for nothing. 然而，这些工作都是劳而无功。
英英解释
adv.
1. up to the present time
2. used in negative statement to describe a situation that has existed up to this point or up to the pr
3. to a greater degree or extent; used with comparisons
4. within an indefinite time or at an unspecified future time
5. used after a superlative
6. despite anything to the contrary (usually following a concession)
