區別是：Not at all指的是一點也不，根本不。certainly not指的是不，當然不行;決不。例句辨析：Not at all1、I am not an obsessive. Not at all. 我不是個強迫症患者，完全不是。2、It"s not at all certain whether I"ll come tomorrow. 我明天還不定來不來呢。3、I"m not at all secretive, and I"m pretty good at calling a spade a spade. 我不會遮遮掩掩，我喜歡直言不諱。certainly not1、He"s very attractive, though certainly not a ladykiller.他很有魅力，雖然還不至於使女人一見傾心。2、I don"t know just exactly how old his child is, but certainly not older than twenty.他的孩子究竟多大我不清楚，反正不超過20歲。3、She might be a little common at times, but she was certainly not boring. 她有時候可能有點粗俗，但絕對不會讓人生厭。

certainly not 英[萻Y:tnli nTt] 美[萻Ztnli nɑt]

[詞典] 不，當然不行; 決不;

[例句]I"m certainly not scared of him

我當然不怕他。