certianly与sure的区别
sure 既可用做形容词，也可用作副词。 1、 作形容词时，意为“肯定，确信，有把握”。常用以下句型： 1）be sure of /about 相信，确信 例如：I am sure of /about his success .我确信他会成功。 2）be sure to 一定，务必 例如：Be sure to come earlier tomorrow. 请明天必须早点来。 3）be sure +that 从句 例如：I am sure (that) I left the book on...