空 (kōng) is a Chinese character meaning “empty”. It is written from 穴 (cave; hole) and 工 (work), one above the other, and takes 8 strokes. It has a second reading, kòng, which turns up in 空闲 — here the two readings are two separate things to learn, not one card with two answers.
Build the character for “empty; sky”
Four steps: break it apart, build it, recall it, use it in a word.
StartLearn this character
Structure
穴 + 工
Top–bottom structure
Structure from: 现代字形拆分（IDS ⿱穴工；笔画核验 穴5 + 工3 = 8）
Memory aid
A cave (穴) with nothing but work (工) left inside it — the cave is hollow, empty. Both parts are really in this character.
This is a memory aid, not the historical origin.
Stroke order
8 strokes
In real words
- 太空tài kōngouter space空 = kōng
- 空旷kōng kuàngopen and spacious; wide open空 = kōng
- 空袭kōng xíair raid; air strike空 = kōng
- 空调kōng tiáoair conditioner; air conditioning空 = kōng
- 航空háng kōngaviation; air (travel)空 = kōng
Go deeper
All readings
empty; sky
empty; hollow; void; air; sky; in vain
里面没有东西；也指天空、空间。 — studyhanzi 编写
Words with this reading
- 太空tài kōngouter space空 = kōng
- 空旷kōng kuàngopen and spacious; wide open空 = kōng
- 空袭kōng xíair raid; air strike空 = kōng
- 空调kōng tiáoair conditioner; air conditioning空 = kōng
- 航空háng kōngaviation; air (travel)空 = kōng
free; vacant
free (time); unoccupied; vacant space; a blank
没有被占用的时间或地方。 — studyhanzi 编写
Words with this reading
- 空闲kòng xiánfree time; idle空 = kòng
Sound component
工 family onset shift
Stroke data: hanzi-writer-data (Arphic Public License) · licenses & attributions
Questions people ask about this character
What does 空 mean?
空 (kōng) means empty; hollow; void; air; sky; in vain.
How do you pronounce 空?
Its main reading is kōng. It also has a second reading, kòng, which only shows up in certain words such as 空闲 — so the word tells you the reading, not the character on its own.
Why is 空 sometimes pronounced kòng?
Because it is a multi-reading character: each reading carries a different sense, and the word decides which one applies. In 空闲 it is read kòng.
What parts is 空 made of?
穴 (cave; hole) and 工 (work), one above the other. The recorded source is: 现代字形拆分（IDS ⿱穴工；笔画核验 穴5 + 工3 = 8）. Components are the building blocks of the shape; the radical used for dictionary lookup is a separate thing.
How many strokes does 空 have?
8. You can watch the stroke order on this page, or trace it yourself.
What is the radical of 空?
穴. The radical is how the character is filed in a dictionary — it is not the whole story of how the character is built.
What words use 空?
Common ones are 太空 and 空旷. The reading of 空 is not the same in every word, so each word on this page shows which reading applies.