空

2 readings · tap one to hear it

empty; air; sky; in vain

Sound it out + = · + =

Formation & memory

Break the character into parts you already know.

Phono-semantic compound (形声字)

穴 meaning “cave” + 工 sound ( gōng )

Components 穴工

empty · Heisig RSH #1073

穴 hole + I-beam

Keyword method from Heisig's Remembering Simplified Hanzi.

The most common words first — learning a character in context makes it stick.

Word	Pinyin	Meaning
空无一人	kōng wú yī rén	not a soul in sight (idiom)
空心儿	kòng xīn r	erhua variant of 空心[kong4 xin1]
天马行空	tiān mǎ xíng kōng	like a heavenly steed, soaring across the skies (idiom); (of writing, calligraphy etc) bol…
空气动力学	kōng qì dòng lì xué	aerodynamics
空子	kòng zi	gap; unoccupied space or time; fig. gap; loophole
有空儿	yǒu kòng r	erhua form of 有空[you3 kong4]
一空	yī kōng	leaving none left; (sold etc) out
空心面	kōng xīn miàn	macaroni
空头	kōng tóu	phony; so-called; armchair (expert); vain (promise); (finance) short-seller; bear (market)…
中空	zhōng kōng	hollow; empty interior
空中	kōng zhōng	in the sky; in the air
空气动力	kōng qì dòng lì	aerodynamic force
空心	kōng xīn	hollow; (of vegetables) to become hollow or spongy inside; (of a basketball) to swish thro…
空心	kòng xīn	on an empty stomach
空地	kōng dì	air-to-surface (missile)
空地	kòng dì	vacant land; open space
空儿	kòng r	spare time; free time
天空	tiān kōng	sky
空性	kōng xìng	emptiness
空白	kòng bái	blank space

Characters sharing the sound component 工 — compare how they read.

Character	Pinyin	Meaning
工 sound part	gōng	labor, work; laborer, worker
红	hóng	red, vermillion; to blush, to flush; popular
江	jiāng	large river; the Yangtze; surname
经	jīng	the classics; to experience, to undergo
轻	qīng	light, gentle; simple, easy
径	jìng	path, diameter; straight, direct
攻	gōng	to accuse; to assault; to criticize
项	xiàng	neck, nape; item; a term in an equation
氢	qīng	ammonia
贡	gòng	to offer, to contribute; tribute, gifts
虹	hóng	rainbow
缸	gāng	earthen jug, crock, cistern
肛	gāng	anus
巩	gǒng	to bind, to guard, to strengthen; firm, secure, strong
汞	gǒng	mercury (element)
邛	qióng	mound; in distress
豇	jiāng	kidney bean; black-eyed pea
仝	tóng	together, same; surname
巠	jīng	underground river; flowing water