【中文这样说】

我们已经等了半小时了,她还没有来.

【英文对比翻译】

Chinese Style We have been waiting for half an hour. She has still not come.
American Style We have been waiting for half an hour. She has not come yet.

Still常用于肯定句; yet用于疑问句和否定句中，及用于表示怀疑的动词之后, 通常位于句末;在英式英语中通常用于现在完成时或过去完成时