一般过去时改否定句再改一般疑问句,我这有两例子；he worked vevy hard last year和MR.smith bought a ne

he worked vevy hard last year.否定 he didn't work vevy hard last year.疑问 did he work vevy hard last year?MR.smith bought a new car yesterday.否定 MR.smith didn't buy a new car yesterday.疑问 did MR....