肯定句变疑问句的疑惑 英语语法

肯定句变疑问句的疑惑 英语语法 一直以来,肯定句变疑问句,关于主语I变you,还是you 变I,我一直模棱两可.似乎有很多种不同情况.希望英语高手指教.1.I can swim in the river.变一般疑问句 can 表示能力Can you swim in the river?2.You can take the umbrella with you.变一般疑问句 can表示允许Can you can take the umbrella with you?还是Can I can take the umbrella with me?3.It is my bag.变一般疑问句Is it my bag?还是Is it your bag?4.You are reading a book.变为一般疑问句Are you reading a book?还是其他5.I must go to school now?变为一般疑问句Must I go to school now?还是 Must you go to school now?像这些情况,还有其他类似的情况,我自己也不太清晰.什么不能自问自答,还有人称根据句意变化.还请注明出处.答得好的话,