怎么把复数的英语句子改为一般疑问句,否定句和陈述句,怎么把复数的否定句子改为一般疑问句.陈述句

问题描述:

怎么把复数的英语句子改为一般疑问句,否定句和陈述句,怎么把复数的否定句子改为一般疑问句.陈述句
越细越好,举例说明

They are my friends.
否定句 They are not my friends
一般疑问句 Are they your friends
变单数 He/she is my friend
They are not my friends
变一般疑问句 Aren't they your friends