单句改错,下面句子各有一处错误请找出并改正
问题描述：
单句改错,下面句子各有一处错误请找出并改正
last month,they might stay at home
there may have some students playing in the class room
you needn't to sit here
答
last month,they might stay at home stay-be
there may have some students playing in the class room have-be
you needn't to sit here 去年to