1)Be sure of +抽象名詞/doing sth ：主語是人，譯為：主語有把握/確信…
He is sure of his success. = He is sure that he will succeed.
I’m sure of his honesty.
I’m sure of winning the game.
Be sure of + 反身代詞 ：有自信心
She is not sure of herself .
2)be sure about +具體名詞
I’m not sure about two things ——grammar and some of the idioms.
3)Be sure to do sth 主語可人可物、譯為：說話人對句子主語的判斷而不是主語對自身判斷，譯為：“主語一定、必然會…” He is sure to succeed.
It is sure to rain.
Be sure to do 用在祈使句中不表判斷而是提出要求，肯定祈使句中譯為“務必…/一定要…”， Be sure to forget it . 否定祈使句中譯為“千萬別做某事…” Be sure not to do that thing again.
4)Be sure + that 從句：主句主語對賓語從句中人或事的判斷 “…確信某人/某事一定會…” I’m sure that you will make great progress this time . 5) sure 用作副詞時常用于口語中 sure = of course / certainly