就是用法的区别,意思大致相同,表示“确定要做某事”
make sure to do sth 就是sure后面跟动词不定式,有表示将来时的意味
如：i make sure to finish this work later.
be sure of sth/ doing sth 就是sure 后面跟名词或者动名词
如：i 'm sure of having finished this work
be sure that 就是sure 后面跟一个完整的从句,that 可以省略
如：i am sure that i will finish this work later
be certain of/about的用法跟be sure of 相似,后面跟名词或动名词