You are doing your homework?
否定句：You aren't doing your homework.
一般疑问句：Are you doing your homework?
We can play football today?
否定句：We can't play football today?
一般疑问句：Can we play football today?
I visit my grandpa everyday.
否定句：I don't visit my grandpa everyday
一般疑问句：Do you visit your grandpa everyday?
His brother went to the supermarket yesterday.
否定句：His brother didn't go to the supermarket
一般疑问句：Did his brother go to the supermarket