Usage note
必表示一定、必须。
bì biǎo shì yí dìng 、 bì xū。
必 means certainly or must.
Context note
必常用于书面语和固定表达。
bì cháng yòng yú shū miàn yǔ hé gù dìng biǎo dá。
It is often used in written language and set phrases.
5 examples
必定会成功。
bì dìng huì chéng gōng。
It will certainly succeed.
必然有原因。
bì rán yǒu yuán yīn。
There must be a reason.
不必担心。
bú bì dān xīn。
No need to worry.
这件事必需认真做。
zhè jiàn shì bì xū rèn zhēn zuò。
This matter must be done carefully.
必有收获。
bì yǒu shōu huò。
There will certainly be gains.
5 mini stories
只要努力，必有结果。
zhǐ yào nǔ lì， bì yǒu jié guǒ。
As long as you work hard, there will certainly be results.
老师说学习必先认真。
lǎo shī shuō xué xí bì xiān rèn zhēn。
The teacher said learning must start with seriousness.
这条路必会越来越好。
zhè tiáo lù bì huì yuè lái yuè hǎo。
This road will certainly get better and better.
遇到困难，不必害怕。
yù dào kùn nán， bú bì hài pà。
When facing difficulty, there is no need to be afraid.
他相信明天必定会更好。
tā xiāng xìn míng tiān bì dìng huì gèng hǎo。
He believes tomorrow will certainly be better.
Mini dialogue
出门前
A
上学前，你必带什么东西？
Shàngxué qián, nǐ bì dài shénme dōngxi?
Before going to school, what must you bring?
B
我必带书包和水壶。
Wǒ bì dài shūbāo hé shuǐhú.
I must bring my schoolbag and water bottle.
做作业
A
写汉字时，我必很认真。
Xiě Hànzì shí, wǒ bì hěn rènzhēn.
When writing Chinese characters, I must be very careful.
B
对，我们必一笔一画写清楚。
Duì, wǒmen bì yī bǐ yī huà xiě qīngchǔ.
Right, we must write each stroke clearly.
Related words and contrasts
similar
须
xū
must, have to
More formal; often used in written rules.
similar
得
děi
must, have to
Very common in spoken Chinese.
opposite
不必
bú bì
need not, don't have to
Direct negation of 必.