make sure to do sth、be sure of sth、be sure that 、be certain

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