keep后面接形容词，不接副词，因此是keep quiet，而不是keep quietly。quietly作为副词形式，主要用来修饰动词、形容词或者全句。keep quiet中文翻译为“保持安静”、“保持沉默”。
keep quiet的意思及双语例句
keep quiet意为保持安静（或沉默）。例句有：
1、Keep quiet while you're going around.
巡回参观时要保持安静。
2、The only thing I can do is keep quiet and sit this one out
我唯一能做的就是保持沉默，等待这件事结束。
3、I told her to keep quiet about it
我告诉她此事要保密。
4、Keep quiet or we'll all get nicked.
别出声，要不然我们都会被抓住的。
5、Behave yourself and keep quiet for a while.
规矩点，安安静静地待着！
6、If you don't know the truth, please keep quiet.
如果你不知道真相，就请不要插嘴。
7、You cannot keep her quiet for long; she's irrepressible!
想让她多安静会儿可办不到，她总是欢蹦乱跳的！
8、I think I found it easier than Nell to keep our engagement quiet.
我觉得，我比内尔更容易守得住我们订婚的秘密。
9、If you keep quiet, no one need ever know.
如果你保持沉默，没有人会知道的。
10、I made a small request: that she keep quiet.
我提了一个小小的请求：要她保持安静。
