You really know your stuff!
你对自己的领域确实很精通。
know one's stuff直译过来就是：“了解自己的东西”，这个短语的正确意思是：“精通自己的业务”。因此，当美国人说"You really know your stuff."时，他/她要表达的意思就是"You are really proficient in your own field."、"You are very skillful at your work."、"You know your field very well."。
情景对白：
Boss: Ben, you've done a great job since you came to the company. You really know your stuff. Keep punching.
老板：本，进公司以来，你一直表现很好。你对自己的领域确实很精通，继续好好干吧。
Benjamin: Thank you very much. I will.
本杰明：非常感谢，我会继续努力的。
搭配句积累：
①The boss thumbed up and praised me for my great achievement this month.
老板竖起大拇指表扬我这个月的业绩好。
②You got a promotion from an assistant to the department manager in less than three years.
你在不到三年的时间里，从一名助理升到了部门经理。
③A large sum of money will be given to you as a reward for your research in this field these years.
公司会给你一大笔钱，奖励你这些年来在这个领域做出的研究成果。
④You're doing well as a newcomer.
作为一个新人，你表现很不错。
单词：
1. stuff n. 材料，东西
I don't know anything about this antique stuff.
我对于这种古玩物件一无所知。
'What do you want to know?'—'about life and stuff.'.
“你想知道些什么？”——“关于生命之类的东西。”
3.Not just a website, but a website with stuff.
不单只是一个网站，而是一个真正有料的网站。
2. proficient adj. 精通的
A great number of Egyptians are proficient in foreign languages.
很多埃及人都精通外语。
1.She is proficient in operating the computer.
她操作电脑很熟练。
18.He doesn't look like a proficient in golf.
他看起来不象是个打高尔夫球的专家。
