I don't think he will help me with it.
本句里的主句：I don't think 从句：he will help me with it
当主句主语是第一人称,则反义疑问句跟从句变,否定要转移.（think是一个否定转移的词）把主句里的否定转移到从句中,变成he will not help me with it,will he?
当主句主语不是第一人称,则反义疑问句跟主句变,否定不要转移.比如：
She does't think he will help me with it,does she?