快 (kuài): fast, happy

快 (kuài) is a Chinese character meaning “fast, happy.” Classified as HSK Level 2 (HSK 3.0 Standard, CLEC 2022), it is composed of 忄 (structural) and 夬 (structural). It ranks #366 in character frequency (SUBTLEX-CH corpus).

Etymologically derived, 快 a decisive 夬 will 忄; 夬 also provides the pronunciation. Its radical form 忄 (heart) appears in many related characters such as 忙 (máng, busy), 怎 (zěn, how), 息 (xī, breath).

Spoken pronunciation

Definitions

  1. fast, happy

Etymology & Origin

快

ideographicA decisive 夬 will 忄; 夬 also provides the pronunciation

Decomposition: ⿰忄夬 (layout: left-right)

Stroke Order

1
2
3
4
5
6
7

Practice writing 快 with real-time feedback — trace each stroke in the correct order and build muscle memory in the HanziFeed app.

Words & Compounds

HSK Vocabulary with 快

WordPinyinMeaningHSK
快乐adjectivekuài lèhappy2
愉快adjectiveyú kuàicheerful4
赶快adverbgǎn kuàiquickly4
尽快adverbjǐn kuàias quickly as possible5
快要adverbkuài yàonearly at the point of (doing sth)2
快速adjectivekuài sùfast4
加快verbjiā kuàito accelerate4
痛快adjectivetòng kuàidelighted6
快递nounkuài dìexpress delivery4
快餐nounkuài cānfast food4
凉快adjectiveliáng kuaipleasantly cool (weather etc)3
快捷adjectivekuài jiéquick6

Common Compounds

WordPinyinMeaning
快感nounkuài gǎnpleasure
快活adjectivekuài huohappy
欢快adjectivehuān kuàicheerful and lighthearted
飞快adjectivefēi kuàivery fast
快步nounkuài bùquick step
快车nounkuài chēexpress (train, bus etc)
快餐店nounkuài cān diànfast food shop
特快nountè kuàiexpress (train, delivery etc)
外快nounwài kuàiextra income
快艇nounkuài tǐngspeedboat
爽快adjectiveshuǎng kuairefreshed
快照nounkuài zhào(photography) snapshot
快门nounkuài mén(photography) shutter
轻快adjectiveqīng kuàilight and quick
勤快adjectiveqín kuàidiligent
100
Total compounds
59
As first character
31
As last character
10
As middle character

快 appears in 100 compound words: 59 as the first character, 31 as the last, and 10 in a middle position. Compound statistics computed from SUBTLEX-CH and HSK 3.0 vocabulary data.

Strongest Collocations

Characters that most frequently co-occur with 快 in natural Chinese text, ranked by NPMI (Normalized Pointwise Mutual Information) — a statistical measure of association strength.

速sù
0.611128,996 co-occurrences
很hěn
0.61158,890 co-occurrences
愉yú
0.5876,837 co-occurrences
颤chàn
0.46325 co-occurrences
棋qí
0.4575,412 co-occurrences
幔màn
0.43710 co-occurrences
捷jié
0.4365,154 co-occurrences
艇tǐng
0.4134,746 co-occurrences
就jiù
0.40918,288 co-occurrences
爽shuǎng
0.4061,110 co-occurrences

Idioms & Chengyu (15)

不吐不快bùtǔbùkuàiHSK 6+

to have to get something off one's chest; to have to say something to feel comfortable

phrase
乘龙快婿chénglóng kuàixùHSK 7+

ideal or excellent son-in-law

phrase
大快人心dàkuàirénxīnHSK 3+

to be to the satisfaction of the people

phrase
口快心直kǒukuàixīnzhíHSK 3+

synonym of 心直口快 (xīnzhíkǒukuài, “outspoken and straightforward”)

phrase
快马加鞭kuàimǎjiābiānHSK 7+

to whip the horse to an even swifter speed; to go even faster; to accelerate the speed

phrase
圣诞快乐Shèngdàn kuàilèHSK 7+

Merry Christmas

phrase
手疾眼快shǒu jí yǎn kuàiHSK 5+

see 眼疾手快

phrase
痛快淋漓tòngkuàilínlí

to be extremely joyful

phrase
痛痛快快tòng tong kuài kuàiHSK 4+

immediately; without a moment's hesitation; with alacrity

phrase
先睹为快xiāndǔwéikuàiHSK 7+

to be the first to witness something and regard such action as a pleasure

phrase
心直口快xīn zhí kǒu kuàiHSK 3+

frank and outspoken (idiom); straight speaking; to say what one thinks

phrase
眼疾手快yǎn jí shǒu kuàiHSK 5+

(idiom) quick to notice and react

phrase

Showing 12 of 15 idioms containing 快.

Example Sentences

AI-Generated

快递通常在三天内送达,偏远地区可能需要五天。

Kuàidì tōngcháng zài sān tiān nèi sòngdá, piānyuǎn dìqū kěnéng xūyào wǔ tiān.

Express delivery usually arrives within three days; remote areas may take five days.

EttodayFeb 2026

快讯/马来西亚沙巴凌晨发生7.1强震

kuài xùn mǎ lái xī yà shā bā líng chén fā shēng 7 . 1 qiáng zhèn

News/A 7.1 earthquake struck Sabah, Malaysia in the early morning

EttodayFeb 2026

快讯/闯入川普海湖庄园遭击毙 21岁嫌身分...

kuài xùn chuǎng rù chuān pǔ hǎi hú zhuāng yuán zāo jī bì 2 1 suì xián shēn fēn . . .

News/Breaking into Trump's Mar-a-Lago and being killed by a 21-year-old suspect...

三立新聞網Feb 2026

热/快把记忆体捡回来? 台股4强曝

rè kuài bǎ jì yì tǐ jiǎn huí lái ? tái gǔ 4 qiáng pù

Hot/Quickly pick up the memory back? Taiwan stocks are the top 4 exposed

百度新闻Feb 2026

渝股2025年业绩预快报:金科股份净利润325亿元..

yú gǔ nián yè jì yù kuài bào jīn kē gǔ fèn jìng lì rùn yì yuán . .

Chongqing Stock 2025 Preliminary Earnings Report: Jinke Co., Ltd. Net Profit Hits 32.5 Billion Yuan...

百度新闻Feb 2026

子弟兵给您送祝福啦,快来签收!

zǐ dì bīng gěi nín sòng zhù fú lā , kuài lái qiān shōu !

Our troops are sending you blessings—come sign for them!

Tatoeba

为什么没写作业?快说!

Wèishéme méi xiězuò yè? kuài shuō!

Why didn't you do your homework? Speak up!

Tatoeba

那个学生跑得很快,不是吗?

Nèige xuésheng pǎo de hěn kuài, bù shì ma?

That student runs fast, doesn't he?

Tatoeba

我们很快就到这儿了,不是吗?

Wǒmen hěn kuài jiù dào zhèr le, bù shì ma?

We arrived here fast, didn't we?

Tatoeba

船和火车哪个跑得快?

Chuán hé huǒchē nǎge pǎo de kuài?

Which goes faster, a ship or a train?

Character Family

Homophones — Characters pronounced kuài

Frequently Asked Questions

What does 快 (kuài) mean in Chinese?
快 (kuài) primarily means "fast, happy." It is classified as HSK Level 2, making it a beginner-level character. It ranks #366 in character frequency.
What's the difference between 快 and 慢?
快 (kuài) and 慢 (màn) are often confused. antonym. The key distinguishing feature: 快 (fast) vs 慢 (slow).
How many strokes does 快 have?
快 is written with 7 strokes. The correct stroke order matters for recognition and handwriting speed — practice with the animated guide above to build proper technique.
What is the radical of 快?
The radical associated with 快 is 忄 (heart). This radical appears in many characters related to heart.
What are the components of 快?
快 is composed of: 忄 (structural), 夬 (structural). Its IDS decomposition is ⿰忄夬 with a left-right layout. Understanding the components helps with both memorization and recognizing related characters.
What are common words containing 快?
Common words with 快 include: 快乐 (kuài lè, "happy"); 愉快 (yú kuài, "cheerful"); 赶快 (gǎn kuài, "quickly"); 尽快 (jǐn kuài, "as quickly as possible"); 快要 (kuài yào, "nearly at the point of (doing sth)"). There are over 100 compound words containing this character.
What characters sound the same as 快 (kuài)?
Several characters share the pronunciation kuài: 块 (piece, lump), 筷 (chopstick). Context and tones help distinguish between them in speech and writing.
Is 快 the same in simplified and traditional Chinese?
Yes, 快 is written the same way in both simplified and traditional Chinese.

Practice writing 快 with real-time feedback

Trace stroke sequences, hear spoken pronunciation, and build lasting retention with spaced repetition in the HanziFeed app.

Character data sourced from Unihan (Unicode Consortium), SUBTLEX-CH frequency corpus (Cai & Brysbaert, 2010), and Make Me a Hanzi (stroke data). Collocation strength measured via NPMI (Normalized Pointwise Mutual Information). Verified by the HanziFeed linguistics team.

HSK classification follows the HSK 3.0 Standard (Center for Language Education and Cooperation, CLEC, 2022 revision). Idiom data from Wiktionary (CC BY-SA 3.0).

Data last verified: March 2026.