Picture this, if you are in a library, metro, or cinema and meet some people talking too loud, what will you say to stop them? “Please be quiet” or “be quiet, please” is a polite way. Of course some will use a more angrier way like “shut up” to stop them. In a word, different phrases stand for different emotions. That is one of the most important tips that you should bear in mind when learning to speak Chinese. We need to use appropriate phrases to express our opinions in different situations. In the below part, I list five common ways of how to say be quiet in Mandarin.
麻烦安静一点，má fán ān jìnɡ yì diǎn in Chinese pinyin, is one of the commonest way we use in daily life. It is the same with “be quiet, please” in Enlighs. It not only shows our politeness but expresses our tough attitude when asking people to be quiet. You can use this phrase in any situations. It won’t irritate others.
请说话小声一点 is another way to express “please be quiet in Chinese”, which means “please speaker lower”. It’s pinyin is qǐnɡ shuō huà xiǎo shēnɡ yì diǎn. xiǎo diǎn shēnɡ and xiǎo shēnɡ diǎn are two abbreviations of this phrase which are concise.
请保持安静，qǐnɡ bǎo chí ān jìnɡ in pinyin, is a formal expression in Chinese. You can hear it on the loudspeaker in some public places like metro, museum, and cinema. It is usually an announcement in these public places. But we seldom use it to ask one or two persons to be quiet in our daily life.
不要吵 also means “be quiet”. It is a common expression in daily life as well. It is used frequently in situations where parents stop their child from talking and teachers ask students to keep silent in class.
This is a relatively rude expression. We usually use it when we are angry. For example, if someone spoke too loud and you already tried to stop him in a polite way but it didn’t work, you can say 闭嘴 (bì zuǐ) to express your anger. Besides, 闭嘴 can be also used to stop someone from saying something. For example, you and your friend visit a leader and your friend keep saying which obviously annoy the leader. You have given your friend a hint but he did not get the point and keep blalabla, you may say 闭嘴 to tell him what a big mistake he made.