肯定句用something,否定句用anything,疑问句用anything,但在can,may,could等请求疑问句中仍用something
eg:Do you want something to drink?
Is there anyting interesting in the book?
I have something to tell you.
I don't have anything to tell you.
在疑问句中 somenthing 和 anythig 怎么用?什么时候该用哪个?