Correct

心知肚明

/ xīn zhī dù míng / 
Strokes
https://i.cchatty2.com/filters:format(webp)/fit-in/684x0/img/202102/心知肚明-Chinese-idioms-Cchatty-ab333aa3-3570-4524-a2f8-6016dc93d492-1612777066.jpg

Collocation

1
做到心知肚明
2
心知肚明的事情
3
应该是心知肚明
4
大家心知肚明

Definition

心知肚明

Literally means:

have tacit under standing

Actually means:

It often indicates that one knows the situation, but does not want to tell the details.

表示对某事心里非常明白。常含有尽管明白,但不想说出详细情况的意味。

Example

Used as predicate, object or attributive. (作谓语、宾语、定语)
1
Qíshí
其实
  
,
yǒuxiē
有些
dōngxī
东西
dàjiā
大家
xīnzhīdǔmíng
心知肚明
  
,
méiyǒu
没有
bìyào
必要
ná
拿
chūlái
出来
duō
多
shuō
说
  
。

In fact, there are some things that we all know, there is no need to take out more to say.

2
Fángdìchǎnshāng
房地产商
huòqǔ
获取
bàolì
暴利
  
,
zhè
这
shì
是
xīnzhīdǔmíng
心知肚明
de
的
shì
事
  
,
hái
还
xūyào
需要
wǒmen
我们
duōfèikǒushé
多费口舌
ma
吗
  
?

Real estate developers to obtain windfall profits, this is a well-known thing, but also need us to pay more words?

3
Yǒuxiē
有些
chǎngshāng
厂商
zài
在
guǎnggào
广告
lǐ
里
kuādà
夸大
chǎnpǐn
产品
de
的
xiàoguǒ
效果
  
,
jiūjìng
究竟
wèile
为了
shénme
什么
mùdì
目的
  
?
Dàjiā
大家
yīnggāi
应该
dōu
都
shì
是
xīnzhīdǔmíng
心知肚明
de
的
  
。

What is the purpose of some manufacturers to exaggerate the performance of their products in advertisements? Everyone should know.