be sure of ~ vs be sure to

[향상일로]

▶ be sure of ~  : 주어’가 확신하는 것이다.

▶ be sure to do : 확신하는 주체가 언제나 ‘I' 이다.

   He is sure of success. = He is sure that he will succeed.

   He is sure to succeed. = I am sure that he will succeed.