it is when you intentionally make yourself focus on something.这句话没有语法错误么?

focus应该改为focused,因为focus/concentrate.on sth “集中.于某事上”,这里yourself是宾语,focus on...是宾语补足语,宾语与宾语补足语是逻辑上的主谓关系,focus yourself on sth “使你自己专注于某事”,可见,yourself与focus是被动关系.
应该是强调句式,但,省略了后半句.强调句结构式 It is/was +被强调部分+that/who+原句的其余部分.It is when you intentionally make yourself focused on something that...(此处应该是上文提到的内容）比如可能是“you can achieve success"
应该能帮到你吧,希望可以被采纳哟