I make him study hard.有语法错误么

I make him study hard.有语法错误么 I study vary hard to catch him I make him clean the room这句话有语法错误吗? I sometimes study grammar.有语法错误吗? I _______ (make a decision) to study hard this semester. I will study hard and make progress bit by bit. I should study hard and should study well make a little prog I must study hard? 有study study hard,day day up的说法么 i kept telling him that he should study hard but it didn't f Someone is waiting for me,I will study hard,for him, and for Study hard work hard, to finish what I'm after!最后这句语法有问题么,什么