壹、用於回答感謝,意為“不用謝；不客氣”.如：
A：thank you very much. 多謝妳了.
B：Not at all. 不客氣.
A：Thanks for helping me. 謝謝妳幫助我.
B：Not at all. I enjoyed it. 別客氣,很高興能幫妳.
A：thank you very much. 非常感謝妳.
B：Not at all. It was the least I could do. 不用謝,這是我應該做的.
二、用於回答帶有感謝性質的客套話,意為“沒什麽；哪裏哪裏”.如：
A：You are very kind. 妳真好.
B：Not at all. 沒什麽.
A：It’s very kind of you. 妳真客氣.
B：Not at all. 哪裏哪裏.
三、用於回答道歉,意為“沒關系”.如：
A：I’m sorry I’m late. 對不起,我遲到了.
B：Oh, not at all, do come in. 噢,沒關系,請進來.
A：I’m sorry to keep you waiting. 對不起,讓妳久等了.
B：Oh, not at all. I’ve been here only a few minutes. 哦,沒關系,我也剛到幾分鐘.
四、用來表示否定(是No的加強說法),意為“壹點也不；完全不”.如：
A：Are you busy? 妳忙嗎?
B：Not at all. 壹點不忙.
A：Is it difficult to study English? 英語難學嗎?
B：Not at all. 壹點不難.
A：I’ll be away on a business trip. Would you mind looking after my cat? 我要因公出差,請幫我照看壹下我的貓,妳介意嗎?
B：Not at all. I’ll be happy to. 壹點不介意,我很樂意. certainly not的意思就很簡單：才不,當然不：Do you think everyone in China will use cash by the year of 2020?
------Certainly not!