Usage note
前后表示前面和后面，也表示时间先后。
qián hòu biǎo shì qián miàn hé hòu miàn， yě biǎo shì shí jiān xiān hòu。
Before and after means front and back, and it also means time order.
Context note
前后常出现在位置、顺序和时间里。
qián hòu cháng chū xiàn zài wèi zhì 、 shùn xù hé shí jiān lǐ。
Before and after often appears with location, order, and time.
5 examples
前后都有树。
qián hòu dōu yǒu shù。
There are trees in front and behind.
事情前后要想清楚。
shì qíng qián hòu yào xiǎng qīng chǔ。
Think through the matter before and after.
前后左右。
qián hòu zuǒ yòu。
Front, back, left, and right.
前后不一样。
qián hòu bù yí yàng。
Before and after are different.
他前后都看了看。
tā qián hòu dōu kàn le kàn。
He looked both in front and behind.
5 mini stories
我把前后都看了一遍，才过马路。
wǒ bǎ qián hòu dōu kàn le yí biàn， cái guò mǎ lù。
I looked both in front and behind before crossing the road.
老师说前后要连起来看，才会明白。
lǎo shī shuō qián hòu yào lián qǐ lái kàn， cái huì míng bái。
The teacher said we should look at the before and after together to understand.
这条路前后都有很多车。
zhè tiáo lù qián hòu dōu yǒu hěn duō chē。
There are many cars both in front and behind on this road.
事情前后我都记得很清楚。
shì qíng qián hòu wǒ dōu jì de hěn qīng chǔ。
I remember the matter clearly from beginning to end.
前后比较一下，就知道哪里需要改。
qián hòu bǐ jiào yí xià， jiù zhī dào nǎ lǐ xū yào gǎi。
Compare before and after, and you will know what needs to be changed.
Mini dialogue
做作业前后
A
你写作业前后会做什么？
Nǐ xiě zuòyè qián hòu huì zuò shénme?
What do you do before and after doing homework?
B
写作业前我先洗手，写完后收拾书包。
Xiě zuòyè qián wǒ xiān xǐshǒu, xiě wán hòu shōushi shūbāo.
Before homework I wash my hands, after finishing I pack my schoolbag.
吃饭前后
A
吃饭前后要注意什么？
Chīfàn qián hòu yào zhùyì shénme?
What should we pay attention to before and after eating?
B
饭前要洗手，饭后要漱口。
Fàn qián yào xǐshǒu, fàn hòu yào shùkǒu.
Wash hands before meals, rinse mouth after meals.
Related words and contrasts
similar
左右
zuǒ yòu
around; about
前后 can also mean 'around' a time, similar to 左右
related
先后
xiān hòu
successively; order
先后 focuses on the sequence of events
contrast
始终
shǐ zhōng
from beginning to end
始终 means 'throughout', while 前后 refers to before and after a point