at all : 解析:　　at all 常用于否定句以加强语气,常见结构是“…not… at all”或 “…not at all…”,意思是“完全不”“根本不”“一点也不”。例如:
I’m not at all tired. 我一点都不累。
The police said baby Robert didn’t cry at all. 警察说,罗伯特这孩子根本没哭。
She added that having conversations with friends was not helpful at all. 她补充说,跟朋友们交谈根本没有帮助。
at all也可用于条件句句末以加强语气。例如:
Do it well if you do it at all. 要做就要做好它。
注意:　　not at all 还可作为回答对方道谢时的客套话,可译成“别客气”。例如:
— Thank you very much. 谢谢您。
— Not at all.别客气。