"can you tell me something about Yunnan?" 中为什么用something而不用anything?

something与some一样常用于肯定句，而anything与any一样常用于否定句和疑问句。不过，在表示请求、建议或征求意见的疑问句中常用some或something。在表达“任何”这一含义时肯定句中常用any或anything。例如：
1.——I feel a bit hungry.
——Why don't you have some bread?（86年高考题）
2.Would you like something to drink?
3.You can get it in any department store.这东西你在哪个百货商店都买得到，
4.I believe anything he says.

在表示请求，并希望得到肯定回答时用something。例如
Would you like to have something to eat?

something 意味一些事
anything 意味任何事
从意思上来分析用something
并非只要是疑问句和否定句就用anything代替something

something 在这里表示婉转的请求和询问，anything的语气比较强烈。

当句意表恳求，渴望的到丢方肯定时，都用含some的词回答。
列举：could ,would提问时用含some的词回答。
could you drink some tea?(对方想得到肯定回答）