Correct

必须 vs 必需

/ bìxū vs bìxū /
Strokes

Definition

必须 is an Auxiliary verb, 必需 is a Verb, which means [must; have to; essential; indispensable].

Example

必须 is an auxiliary verb used in front of the main verb, indicating the meaning of "must, ought to".

2)
3)必须 and the main verb can be used together as the attributive modifying the subject or object,e.g.:
1
Tōngguò
通过
hǎiguān
海关
shí
必须
jiǎnchá
检查
zhào
护照
  

Passport is required to show at the Customs.

2
jiā
大家
必须
tuánjié
团结
zuò
合作
  
,
gòngtóng
共同
克服
kùnnan
困难
  

All of us should hang together to defeat difficulties.

If there is an adverbial, it must be placed before the main verb and after 必须.
3
Zhè
jiàn
shì
必须
qīn
亲自
pǎo
tàng
  

As for the matter, you must go there in person.

4
Zhège
这个
wèn
问题
men
我们
必须
zài
仔细
yánjiū
研究
xià
  

We must study it carefully again.

必须 and the main verb can be used together as the attributive modifying the subject or object.
5
Huánbǎo
环保
shì
měige
每个
rén
dōu
必须
zuò
de
shì
  

Environmental protection is what everyone should do.

6
Zhè
shì
ge
必须
zhu
记住
de
shù
数字
  

These numbers must be memorized/born in mind.

必需 is a verb meaning indispensability and usually functions as an attributive.
7
Dànbáizhì
蛋白质
shì
rén
人体
必需
de
yíngyǎng
营养
  

Protein is vital to our body.

8
měiyuè
每月
必需
de
shēnghuófèi
生活费
shì
800
800
yuán
  

His monthly living expen- ses are 800 yuan at least.

9
  
miàn
  
yóu
  
yán
shì
cháng
日常
shēnghuó
生活
suǒ
必需
de
  

Rice, flour, oil and salt are all daily necessities in life.

Related

必需必须