⮪ LessonsUpdated 2/19/2025 - 23 min read

Chinese Classifiers

Modern Chinese varieties frequently use classifiers, or measure words, to pair numerals or demonstratives with nouns. For example, in a phrase like "three books" (三本書), the classifier 本 is placed between the numeral 三 (three) and the noun 書 (books). Classifiers are typically omitted when nouns appear without determiners that quantify or specify them. They also serve additional purposes, such as indicating plurality or indefinite quantities when used after a noun or repeated.

The terms classifier and measure word are often used interchangeably to refer to 量詞 (liàngcí), but they can be distinguished. Classifiers are particles without specific meaning, while measure words denote specific quantities (e.g., "drop," "liter"). These are also known as count-classifiers (for count nouns) and mass-classifiers (for mass nouns). Despite these differences, their grammatical behavior is largely the same.

Classifier Neutralization

In Mandarin Chinese, "個" (gè) is a general classifier used for people, abstract concepts, and words lacking specific classifiers (e.g., 漢堡 "hànbǎo" "hamburger"). It may also replace specific classifiers like "張" (zhāng) or "條" (tiáo) in informal speech. Since the 1940s, there has been an increasing trend to use "個" in place of specialized classifiers, a phenomenon known as "classifier neutralization" (量詞個化). This is especially common among children, aphasics, and even normal speakers, who use "個" when speaking quickly or informally, often without realizing it. As a result, "個" is much more frequently used in everyday spoken Mandarin than other specific classifiers. However, using the appropriate classifier instead of over-relying on "個" demonstrates a strong command of the Chinese language.

Common Classifiers 普通量詞

個	gè	General classifier for people or objects.	一個人 (yī gè rén) - One person.
張	zhāng	Used for flat objects like paper, tickets, or tables.	一張紙 (yī zhāng zhǐ) - One sheet of paper.
本	běn	Bound items like books.	一本書 (yī běn shū) - One book.
支	zhī	Stick-like objects like pens, pencils, or branches.	一支筆 (yī zhī bǐ) - One pen.
件	jiàn	Used for items of clothing, furniture, or matters.	一件衣服 (yī jiàn yī fú) - One piece of clothing.
輛	liàng	Used for vehicles.	一輛車 (yī liàng chē) - One car.
隻	zhī	Used for animals or one of a pair.	一隻狗 (yī zhī gǒu) - One dog.
本	běn	Plants.	一本樹 (yī běn shù) - One tree.
塊	kuài	Used for chunks, pieces, or currency.	一塊蛋糕 (yī kuài dàn gāo) - One piece of cake.
雙	shuāng	Pairs of objects.	一雙鞋 (yī shuāng xié) - One pair of shoes.
條	tiáo	Long, flexible objects like ropes, rivers, or fish.	一條魚 (yī tiáo yú) - One fish.
頭	tóu	Large animals like cows or pigs.	一頭牛 (yī tóu niú) - One cow.
座	zuò	Large, immovable objects like mountains or buildings.	一座山 (yī zuò shān) - One mountain.
架	jià	Machines, planes, or large instruments.	一架飛機 (yī jià fēi jī) - One airplane.
封	fēng	Letters or sealed documents.	一封信 (yī fēng xìn) - One letter.
片	piàn	Used for thin, flat pieces like leaves or slices.	一片葉子 (yī piàn yè zi) - One leaf.
顆	kē	Small, round objects like stars or grains.	一顆星星 (yī kē xīng xīng) - One star.
粒	lì	Used for tiny, granular objects like rice or sand.	一粒米 (yī lì mǐ) - One grain of rice.
朵	duǒ	Used for flowers or clouds.	一朵花 (yī duǒ huā) - One flower.
匹	pǐ	Horses or other mounted animals.	一匹馬 (yī pǐ mǎ) - One horse.
隻	zhī	Boats or small crafts.	一隻船 (yī zhī chuán) - One boat.
棵	kē	Used for trees or plants.	一棵樹 (yī kē shù) - One tree.
頁	yè	Pages of a book or document.	一頁書 (yī yè shū) - One page of a book.
部	bù	Movies, novels, or machines.	一部電影 (yī bù diàn yǐng) - One movie.
階	jiē	Steps or stages.	一階台階 (yī jiē tái jiē) - One step of a staircase.
台	tái	Used for electronic devices or stage performances.	一台電視 (yī tái diàn shì) - One television.
次	cì	Used for occurrences or repetitions.	一次機會 (yī cì jī huì) - One opportunity.
滴	dī	Used for drops of liquid.	一滴水 (yī dī shuǐ) - One drop of water.

Container Classifers 容器量詞

Like many other languages, Chinese uses the container itself as the classifier for items stored within it.

箱	xiāng	Boxes or containers	一箱書 (yī xiāng shū) - One box of books
碗	wǎn	Bowls	一碗湯 (yī wǎn tāng) - One bowl of soup
瓶	píng	Bottles	一瓶水 (yī píng shuǐ) - One bottle of water
桶	tǒng	Buckets or large containers	一桶油 (yī tǒng yóu) - One bucket of oil
袋	dài	Bags	一袋米 (yī dài mǐ) - One bag of rice
盒	hé	Small boxes or cases	一盒巧克力 (yī hé qiǎo kè lì) - One box of chocolates
罐	guàn	Used for cans or jars	一罐可樂 (yī guàn kě lè) - One can of cola
盤	pán	Plates or trays	一盤菜 (yī pán cài) - One plate of food
簍	lǒu	Baskets or large containers	一簍水果 (yī lǒu shuǐ guǒ) - One basket of fruit
盅	zhōng	Small bowls (usually of liquids)	一盅茶 (yī zhōng chá) - One small bowl of tea
壺	hú	Used for teapots or similar vessels	一壺茶 (yī hú chá) - One teapot of tea
塊	kuài	Used for chunks or pieces	一塊蛋糕 (yī kuài dàn gāo) - One piece of cake
盞	zhǎn	Lamps or cups	一盞燈 (yī zhǎn dēng) - One lamp
碟	dié	Small plates or dishes	一碟餃子 (yī dié jiǎo zi) - One plate of dumplings
本	běn	Bound books or volumes	一本書 (yī běn shū) - One book
串	chuàn	Used for items strung together, like grapes or sausages	一串葡萄 (yī chuàn pú táo) - One bunch of grapes
根	gēn	Long, thin items like ropes or plants	一根藤 (yī gēn téng) - One vine
條	tiáo	Long, thin objects like fish or rods	一條魚 (yī tiáo yú) - One fish
枝	zhī	Stick-like objects like flowers or pens	一枝花 (yī zhī huā) - One flower
筒	tǒng	Used for cylindrical objects like tubes or containers	一筒口香糖 (yī tǒng kǒu xiāng táng) - One tube of chewing gum
袋	dài	Bags or packets	一袋糖果 (yī dài táng guǒ) - One bag of candy
班	bān	Groups or shifts, but can be used metaphorically for containers in large-scale operations	一班貨 (yī bān huò) - One batch of goods
塔	tǎ	Used for towers or tall structures, metaphorically for stacked containers	一塔鐘 (yī tǎ zhōng) - One tower clock

Numeral Classifiers 數詞量詞

Chinese classifiers can be useful to indicate numbers, rough figure, or configuration.

疊	dié	Stacks or piles	一疊書 (yī dié shū) - One stack of books
組	zǔ	Sets or groups	一組工具 (yī zǔ gōng jù) - One set of tools
雙	shuāng	Pairs	一雙鞋 (yī shuāng xié) - One pair of shoes
批	pī	Batches or lots	一批貨物 (yī pī huò wù) - One batch of goods
對	duì	Matching pairs	一對情侶 (yī duì qíng lǚ) - One couple
排	pái	Used for rows or lines	一排椅子 (yī pái yǐ zi) - One row of chairs
串	chuàn	Used for things strung together	一串葡萄 (yī chuàn pú táo) - One bunch of grapes
群	qún	Groups or crowds	一群鳥 (yī qún niǎo) - One flock of birds
套	tào	Sets or suites	一套衣服 (yī tào yī fú) - One set of clothes
把	bǎ	Handfuls or things with handles	一把傘 (yī bǎ sǎn) - One umbrella
份	fèn	Portions or shares	一份報紙 (yī fèn bào zhǐ) - One newspaper
節	jié	Segments or sections	一節火車 (yī jié huǒ chē) - One train car
座	zuò	Large immovable objects	一座橋 (yī zuò qiáo) - One bridge

Nominal

Proper Classifiers

把	bǎ	grip — objects with handle-like parts (knives 刀, scissors 剪刀, swords 劍, keys 鑰匙, pistols 手槍, chairs 椅子, flaming torches or sticks 火)
本	běn	volume — bound print matter (books 書, etc.)
冊	cè	volumes of books (冊 is more common in Traditional Chinese, 冊 in Simplified)
層	céng	layer — cakes, optical discs, etc.; stories of buildings
場	chǎng	stage — public spectacles, games 比賽, drama 戲, film 電影, etc.
處	chù	location, site — ruins 廢墟, construction site 工地, etc.
齣	chū	performance, show — plays 戲, circus 馬戲, etc.
次	cì	time — opportunities 機會, accidents 事故
道	dào	linear projections (light rays 亮光, etc.), orders given by an authority figure 命令, courses (of food) 點心, walls and doors 門, questions 題, number of times (for certain procedures) 工序
頂	dǐng	objects with protruding top (hats 帽子, etc.)
棟	dòng	pillar — buildings 房子
堵	dǔ	walls and encompassing fixtures 牆
頓	dùn	meals 飯
朵	duǒ	flowers 花, clouds 雲
發	fā	projectile weapons, such as bullets 子彈, artillery shells 炮彈, rockets, guided missiles etc.
份	fèn	copy — newspapers 報紙, notarized document 公證, contract 合同
封	fēng	letters 信, mail, fax 傳真
幅	fú	width — paintings 畫兒, curtains, tapestries, photographs or prints (particularly when mounted and displayed on a wall)
桿	gǎn	objects with 'pole' (spears 槍, balance scales, steelyard balance)
個	ge (gè)	individual things, people — generic measure word (usage of this classifier in conjunction with any noun is generally accepted if the person does not know the proper classifier)
根	gēn	thin, slender, pole, stick objects (needles 針, pillars 支柱, telegraph poles, matchsticks, etc.); strands 絲
號	hào	people, workmen (一百多號人); business deals (幾號買賣)
家	jiā	gathering of people (families 人家, companies 公司, etc.), establishments (shops 商店, restaurants 酒店, hotels 飯店)
架	jià	aircraft 飛機, pianos 琴, machines 儀器
件	jiàn	matters (affairs 事情), clothing 衣裳, etc.
屆	jiè	recurring, often annual, conferences 會, class years in a school (e.g. Class of 2006) 畢業生
卷	juǎn	roll — film 膠卷, toilet paper 手紙
棵	kē	trees 樹 and other such flora
顆	kē	kernel — small objects (beans, hearts 心, pearls 珠子, teeth 牙齒, diamonds 鑽石, etc.) pillows, and objects appearing to be small (distant stars 星星 and planets 星球)
口	kǒu	people in villages 人, family members; wells 井; blade 刀
類	lèi	objects of the same type or category — affair 事情, circumstance 情況
粒	lì	grain, small objects such as a grain of rice 米
輛	liàng	wheeled vehicles: automobiles 汽車, bicycles 自行車
列	liè	array — trains 火車
輪	lún	round — competition 比賽, discussions 會談; moon 明月
枚	méi	small, flat objects (coins, medals, stamps); small, round jewelry (rings 戒指, diamonds 鑽石); projectiles (bombs 炸彈, grenades 手榴彈, rockets, satellites); eggs 蛋
門	mén	gate — areas of knowledge (courses 課, languages 語言, majors 專業), also for artillery pieces 大砲
面	miàn	surface — flat objects (mirrors 鏡子, flags 旗子, etc.)
名	míng	honorific, or persons with perceived higher social rank (doctors 醫生, lawyers 律師, politicians, royalty, etc.); in formal occasions or in literary Chinese, also used for any type of person (not necessarily high-ranking, e.g. mother 母親)
盤	pán	flat objects (video cassettes 錄影帶, etc.); literally means 'dishes' and can be used for a plate of food
泡	pào, pāo	classifiers for liquid extractions (tea 茶, urine 尿)
匹	pǐ	horses 馬 and other mounts; also rolls/bolts of cloth 布
篇	piān	written work: papers 論文, articles 文章, novels etc.
片	piàn	slice — flat objects, cards, slices of bread 麵包
起	qǐ	case, instance (兩起大腦炎); batch, group (分兩起出發)
扇	shàn	doors 門, windows 窗戶.
首	shǒu	songs 歌, poems 詩, music 曲子, etc.
水	shuǐ	washings/rinsings (這件衬衫洗了三水了)
艘	sōu	ships 船
所	suǒ	for buildings whose purposes are explicitly stated, e.g. hospitals 醫院. Otherwise can use '座'
臺	tái	heavy objects, esp. machines (TVs 電視機, computers 電腦, etc.); performances (theatre 話劇)
堂	táng	periods of classes 課 (e.g. 'I have two classes today'), suites of furniture
趟	tàng	trips (usually repetitive), scheduled transportation services — flights 班機
題	tí	test/exam questions
挺	tǐng	machine guns 機槍
條	tiáo	strip; long, narrow, flexible objects — (fish 魚, dogs 狗, trousers 褲子, etc.), also for roads 路 and rivers 河, pertaining to human lives, e.g. '兩條人命' two (human) lives, '一條心', lit. 'one heart' (to work as one)
頭	tóu	head — domesticated animals 家畜 (pigs 豬, cows 牛, etc.), hair (only used alongside a modifier)
尾	wěi	tail — fish 魚 (ancient)
位	wèi	polite classifier for people (attached to positions, not names) — workers 工人, director 主任
項	xiàng	item — items, projects — initiative 倡議, ordinances 法令, statements 聲明
宿	xiǔ	nights, overnight stays (住一宿)
樣	yàng	general items of differing attributes
則	zé	sections of text — notice 消息, jokes 笑話/笑话, news 新聞/新闻, etc.
盞	zhǎn	light fixtures (usually lamps 燈/灯), pot of tea etc.
張	zhāng	sheet — flat objects (paper 紙/纸, tables 桌子, etc.), faces 臉/脸, bows, paintings 圖畫/图画, tickets 票, constellations, blankets, bedsheets 床單/床单;
隻	zhī	one of a pair (hands 手, legs); animals (birds 鳥/鸟, cats 貓/猫, etc.)
支	zhī	fairly long, stick-like objects (pens 筆/笔, chopsticks, roses, rifles 槍/枪, etc.), fleets 舰队/艦隊
枝	zhī	alternative form of 支 ('stalk'): can be used for rifles 槍/枪 and flowers
種	zhǒng	types or kinds of objects (animals 動物/动物)
株	zhū	trees 樹/树
柱	zhù	incense 香
尊	zūn	statues 像
座	zuò	large mansion 大厦; mountains 山

Measure Words / Massifiers

把	bǎ	handful (beans, flour, rice, sand); bunch/bundle (chopsticks, matches, sticks); bunch/hand (bananas, carrots, flowers, scallions)
班	bān	classifier for scheduled transport services (trains 火車, bus 公交, subway 地鐵, etc.); group of people; class as in pupils 學生
幫	bāng	group of people (children 孩子, friends 朋友, etc.); gang, band of (bandits 匪徒, bad men 壞蛋, etc.)
包	bāo	packet (cookies 餅乾, cigarettes 香煙, French fries 薯條, screws, etc.)
杯	bēi	cup — container (cup, glass, mug, beaker, etc.) of liquid
輩	bèi	generation, lifetime (people 人)
筆	bǐ	large quantities of money (money 錢, funds 資金, account items 賬目)
串	chuàn	string — sequence of numbers 號碼; pearls 珍珠; grapes 葡萄, skewer/stick (kebabs, satays, etc.)
床	chuáng	bed — blankets 毯子, sheets, quilt
沓	dá	stack of (e.g. paper, or any other paper-like things)
袋	dài	bag — sackfuls, pouchfuls, bagfuls, pocketfuls (flour 麵粉, French fries 薯條, cements 水泥, etc.)
啖	dàn	(Cantonese only) mouthful — amount of food
滴	dī	droplet (water 水, blood 鮮血, other such fluids)
點	diǎn	ideas 意見, suggestions; can also mean a bit (often used to denote amount) — e.g. courage 膽量
段	duàn	length — cables 電線, roadways 路, part as in a drama 臺詞, etc.
堆	duī	pile — trash 垃圾, sand 沙子, etc.
對	duì	pair — couple 夫妻, partner 搭檔, ring 戒指, earrings 耳環, bracelet 手鐲
服	fú	dose (medicine 藥)
副	fù	set — objects which come in pairs (gloves 手套, insole, couplets, etc.) also for spectacles/glasses 眼鏡, mahjong 麻將, Chinese chess 象棋; pack of cards 牌
股	gǔ	flows (of air 氣, smell 香味, influence 潮流, etc.)
管	guǎn	tube — toothpaste and things that comes in tubes
罐	guàn	for canned beverages (e.g. soda), milk powder, sardine, etc.; also for air tank, nitrogen tank, etc.
行	háng	row — objects which form lines (words 詞, etc.); occupations in a field (idiom, spoken language)
盒	hé	objects in a small box or case (e.g. mooncakes, tapes)
戶	hù	households (户 is common in handwritten Traditional Chinese) — household 人家
壺	hú	liquids (usually drink) in a pot (tea, or sometimes rice wine) or kettle (usually water)
伙	huǒ	bands of people such as gangs or hoodlums; group of people (non-derogatory in some dialect)
劑	jì	dose (medicine 藥)
節	jié	section of bamboo 竹子, sugarcane, etc.; branch of tree; a class period at school 課; columnar batteries, carriages of train
句	jù	sentences 句子, quotes 引用, lines 臺詞, etc.
塊	kuài	chunk, lump, piece — land 地, stones 石頭, cake 蛋糕, bread 麵包, candy 糖, tofu 豆腐, etc.; yuan (widely used in spoken language)
捆	kǔn	sets of bundled objects, usually pole-, rope- or stick-like stuffs (e.g. matchsticks 火柴, straw, wire, etc.)
排	pái	row — seats 座位, lanterns 燈籠, aspen, etc.
批	pī	shipment — used for large number of people or large amount of commodity, mass-produced objects (products 產品, laptops, etc.) or supplies
瓶	píng	objects in bottle, vial, or flask (e.g. lemonade, water, troche, etc.)
期	qī	(issues of) periodicals 期刊, magazine 雜誌
群	qún	group (people, students 學生, etc.), herd (e.g. birds 鳥, horse 馬, etc.)
束	shù	bundle of flowers 花; light 光, laser
雙	shuāng	pair — chopsticks 筷子, shoes 鞋, etc.
套	tào	set — books 書, teaware 茶具, collectibles, clothes 衣裳, etc.
聽	tīng	for canned beverages (e.g. soda, cola)
團	tuán	ball — (balls of yarn 毛線, cotton, etc.)
坨	tuó	lump — mud 泥, feces 糞便
碗	wǎn	for food in bowl (e.g. soup 湯, rice 米飯, congee 粥, wonton 餛飩)
些	xiē	some — general massifier. Only used in the form 一些, or without a number
陣	zhèn	gust, burst — events with short durations (e.g. lightning storms, gusts of wind 風, etc.)
注	zhù	a pour of water, tea (liquid); a bet — lottery 彩票
組	zǔ	set — general mass-classifier for sets of objects (batteries 電池, planets 行星, variables 變量, data 數據, etc.)

A set "組" is usually assumed to have two or more objects. But there are also exceptions: depends on what object the classifier is used for, the quantity of objects in sets may be assumed without context. When assumed, the classifier usually falls back to play a similar role to either 雙, 副 or 對: for example, when used for certain objects that come in pairs, e.g. 搭檔, represented as 一組搭檔 (一對搭檔 is valid), here the quantity in each set is assumed to be two (i.e. one pair). Note that when used for other naturally paired things, like chopsticks 筷子, represented as *一組筷子/一组筷子; here the quantity of objects is unspecified if no context specific it, as people never use 組/组 for chopsticks as a natural in-pair object classifier (That is, except for certain objects like 搭檔/搭档, the classifier 組/组 won't fallback to 雙/双, 副 et al. when used for objects in pairs.)

Measure Units - 量詞

Time - 時間

毫秒	háo miǎo	millisecond
秒	miǎo	second
分	fēn	minute
天 / 日	tiān / rì	day
週	zhōu	week
月	yuè	month
年	nián	year
歲	suì	year of age
周年	zhōu nián	anniversary
世紀	shì jì	century

Ten- and thousand-year durations are not nominalized in Chinese. Instead of using specific terms like "decade" or "millennium", the expression is simply a number followed by the time unit. For example, "decade" is expressed as "十年" (shí nián), meaning "ten years," and "millennium" as "千年" (qiān nián), meaning "thousand years". This approach is more descriptive, directly indicating the number of years without relying on a distinct noun form for the time period.

Weight - 重量

克	kè	gram
兩	liǎng	50 grams (1/10 jīn), historically 1/16 jīn
加崙	jiālùn	gallon
斤	jīn	catty/pound (1/2 kilogram)
公斤	gōngjīn	metric jīn, kilogram
千克	qiānkè	kilogram
噸	dūn	ton

Length / Distance - 長度 / 距離

公分	gōngfēn	metric fēn, centimeter
厘米	límǐ	centimeter (more common in mainland China and Hong Kong)
寸	cùn	Chinese inch (1/3 of a decimeter)
吋	cùn	British inch
尺	chǐ	Chinese foot (1/3 of a meter)
呎	chǐ	British foot
英尺	yīngchǐ	British foot
公尺	gōngchǐ	metric chǐ, meter
米	mǐ	meter
里	lǐ	lǐ (500 meters)
哩	lǐ	British mile/Statute mile (5280 British feet)
英里	yīnglǐ	British mile/Statute mile
海里	hǎilǐ	nautical mile (1852 meters, about 6076 British feet)
公里	gōnglǐ	kilometer (1000 meters)
天文單位	tiānwéndānwèi	astronomical unit
光年	guāngnián	light year
秒差距	miǎochājù	parsec (approx. 3.26 light-years or 30.9 trillion kilometers)

Money - 錢

In referring to the physical property of money such as cash (鈔票, chāo piào) or check (支票, zhī piào), the appropriate measure word would be "張" (zhāng).

Due to inflation, 分 coins are no longer in use in either China or Taiwan. 角 coins have also become obsolete in Taiwan, but the colloquial equivalent "毛" can still be heard in conversation. 角 coins are still in use in China, but their role in everyday transactions is steadily shrinking due to inflation and the widespread adoption of mobile payments. The 5 角 coin (representing 50¢) remains more common than the 1 角 coin in practical scenarios.

Term	Pinyin	Definition	Minted in China	Minted in Taiwan
圓	yuán	yuán, ¥ (main unit of currency) — both 圓/元 forms acceptable	✓	✓
塊	kuài	block, yuán (colloquial term similar to 'quid' or 'buck')	✓	✓
角	jiǎo	jiǎo, dime, tenpence (1/10 yuán)	✓	✗
毛	máo	máo, dime, tenpence (slang for 1/10 yuán)	✗	✗
分	fēn	fēn, cent, penny (1/100 yuán)	✗	✗

Verbal Classifiers

Verbal classifiers are special markers added to verbs to show how an action is done, like whether something is picked up, thrown, or carried. They give extra details about the shape, size, or movement of the object in the action.

把	bǎ	a single action or attempt, often informal and action-focused, used in gaming or casual contexts (e.g., 打一把遊戲, 拼一把, 來一把)
遍	biàn	number of times an action has been completed, emphasizing length and effort (e.g., 改了三遍, 把課文讀一遍)
筆	bǐ	a single action of writing or drawing (e.g., 記一筆, 畫一筆)
場	chǎng	length of an event taking place within another event (e.g., 哭一場, 演一場, 一場戲, 一場表演); also used for weather-related occurrences (e.g., 一場大雨, 一場風波)
次	cì	times - refers to number of occurrences regardless of completion (e.g., 每次, 上一次, 下一次, 試了五次, 三次機會)
頓	dùn	actions without repetition (e.g., 打一頓, 罵一頓, 一頓打, 一頓罵); also used for meals (e.g., 吃一頓飯)
番	fān	actions or events with a qualitative result or effort (e.g., 想了一番, 試了一番)
回	huí	occurrences (used colloquially) (e.g., 瀟灑一回, 來一回, 走一回)
面	miàn	encounters or meetings (e.g., 見一面, 談一面)
聲	shēng	cries, shouts, etc. (e.g., 砰的一聲, 嘩一聲, 滴滴兩聲, 一聲響)
趟	tàng	trips, visitations, etc. (e.g., 走一趟, 去一趟, 一趟下來)
通	tōng	a complete action of communication or passage (e.g., 打了一通電話, 繞一通)
下	xià	brief and often sudden actions (e.g., 咔嚓一下, 噌的一下, 跳兩下); also used as weakened injunctive mood (e.g., 來一下, 幫我一下, 一下下)