I have just eaten breakfast 否定句 I haven't eaten breakfast yet. 疑问句并作可否回答 Have you eaten breakfast yet No,I haven't. 不明白的再问哟,请及时采纳,多谢! 再问： he already has changed his diet 再答： He hasn't changed his diet yet. Has he changed his diet yet ? Yes, he has. No, he hasn't.
