still后用肯定还是否定？

两个都可以

“still”既可用于肯定句又可用于否定句，表示动作或状态的持续。
如：
1) She still likes him.
2) I still can not understand you.
注意：“still”置于动词前后，会使句意发生变化。
如：
1) He is still standing. (continue to stand)
2) He is standing still. (=standing motionless)

不可以。语句不通了。

肯定啦