I don't think he will study hard改为反意疑问句

反意疑问句的陈述部分为宾语从句时，或袜一般要根据主弊姿句完成反义疑问句。但宾语从句的谓语动词是think，believe, suppose等词时，完成反义疑问句要看主句的主语是第几人称，如果主句主语是第一人称衫卜激，完成反义疑问句时，人称时态看从句，肯定否定看主句，如I don’t think he is right,is he?　　如果主句主语不是第一人称，而是二三人称，完成反义时要根据主句完成，如：You don't think she is ringt,do you?

will he 否定转移句，变从句且吧not要考虑进去

i don't think he will study hard，will he？