Since the Chinese language environment is so important for foreigners to study Mandarin Chinese, they should learn more in the conversations with Chinese people. For example, when you hear Chinese people say谁说不是呢, it might be difficult for you to understand because it seems a sentence with negative tone. However, as a matter of fact, it means to fully agree with what the other party has said. Let‘s take the following dialogue as an example. 甲：咱们真不应该买这便宜货！乙：谁说不是呢！便宜无好货.

There are many other expressions with the character 谁, meaning “who”. But the meaning might be different when it applied to the practical situations. One pattern you should know is 谁也别说谁, which indicates that the two parties should not blame on each other but should make a self-criticism like你俩谁也别说谁，都好好想想自己的错吧.

There are many uncertain things in your daily life. If you intend to express not sure about something, the structure谁知道呢might be helpful. Those foreign students who learn Chinese online free should know when Chinese people say 谁知道呢, they intend to indicate that the things in the future is hard to predict. For example, 甲：我看这次北京队一定打不过上海队。乙：谁知道呢，足球场上什么事都有可能发生.

You may also hear many sentences with the words什么but not questions such as 什么钱不钱的，你就拿去用吧. In fact, 什么A不A的is the structure to show not to care about much about the other party’s words. For instance, 甲：这鞋不好看。乙：什么好看不好看的， 舒服就行. When you learn Mandarin Chinese, you should also know the structure 什么A呀B的expresses the same meaning. A and B are words that are often polite to each other in meanings like 什么你呀我的，咱们是朋友，不要这么客气.