最好做:had  better  do  sth  例:you  had  better  finish  your  homework  at  home  你最好在家完成作业. 否定形式: 最好别做  had  better  not  do  sth  例,you  had  better  not  go  out你最好不要出去
最好做.是better to do /better doing还是better do