用现在完成时造句否定句

疑问句：Are you leaving already?你这么早就要走了吗？否定句：I'm not doing anything right now.我现在没做什么事情。2、一般过去时：肯定句：He climbed a tree.他爬上了一棵树。疑问句：Did he climb a tree?他爬树了吗？否定句：I didn't know you like coffee.我不知道你喜欢喝咖啡。