Usage note
“信”就是写在纸上的话，寄给远方的人看。
“xìn” jiù shì xiě zài zhǐ shàng de huà, jì gěi yuǎn fāng de rén kàn.
A letter is a written message on paper that you send to someone far away.
Context note
信是写给别人看的话，放在信封里寄出去。
Xìn shì xiě gěi biérén kàn de huà, fàng zài xìnfēng lǐ jì chūqù.
A letter is a written message you send to someone in an envelope.
5 examples
我写了一封信给妈妈。
wǒ xiě le yì fēng xìn gěi mā ma。
I wrote a letter to my mom.
他收到了一封来自远方的信。
tā shōu dào le yì fēng lái zì yuǎn fāng de xìn。
He received a letter from afar.
公司之间会通过信件进行沟通。
gōng sī zhī jiān huì tōng guò xìn jiàn jìn xíng gōu tōng。
Companies communicate with each other through letters.
这是一封感谢信。
zhè shì yì fēng gǎn xiè xìn。
This is a thank-you letter.
他把信放在桌子上。
tā bǎ xìn fàng zài zhuō zi shàng。
He put the letter on the table.
5 mini stories
小明给朋友写了一封信，告诉他学校的事情。
xiǎo míng gěi péng yǒu xiě le yì fēng xìn， gào sù tā xué xiào de shì qíng。
Xiaoming wrote a letter to his friend, telling him about things at school.
妈妈收到一封来自国外的信，里面有很多照片。
mā ma shōu dào yì fēng lái zì guó wài de xìn， lǐ miàn yǒu hěn duō zhào piàn。
Mom received a letter from abroad, which contained many photos.
爸爸写了一封感谢信给老板，表达对公司的感激之情。
bà ba xiě le yì fēng gǎn xiè xìn gěi lǎo bǎn， biǎo dá duì gōng sī de gǎn jī zhī qíng。
Dad wrote a thank-you letter to the boss, expressing his gratitude to the company.
姐姐把信放在抽屉里，准备寄出去。
jiě jie bǎ xìn fàng zài chōu tì lǐ， zhǔn bèi jì chū qù。
Sister put the letter in the drawer, planning to send it out.
他们收到了一封来自亲戚的信，里面有很多家人的消息。
tā men shōu dào le yì fēng lái zì qīn qi de xìn， lǐ miàn yǒu hěn duō jiā rén de xiāo xī。
They received a letter from a relative, which contained many updates about family members.
Mini dialogue
写信
A
你在做什么？
Nǐ zài zuò shénme?
What are you doing?
B
我在给奶奶写一封信。
Wǒ zài gěi nǎinai xiě yī fēng xìn.
I am writing a letter to grandma.
收到信
A
你今天收到信了吗？
Nǐ jīntiān shōudào xìn le ma?
Did you receive a letter today?
B
收到了，这封信是朋友寄来的。
Shōudào le, zhè fēng xìn shì péngyou jì lái de.
Yes, I did. This letter was sent by a friend.
Related words and contrasts
related
信封
xìn fēng
envelope
The paper cover you put a letter in before mailing it.
related
信箱
xìn xiāng
mailbox
The box where you receive or send letters.
related
邮票
yóu piào
stamp
A small sticker you put on a letter to pay for mailing.