What does 空 mean in Japanese?
空 means sky in Japanese, and it is also the kanji for empty or vacant. Both senses are connected by the idea of open, hollow space. The character combines the cave radical (穴) with 工 (work), which helps explain the idea of open or hollow space. Context shows which meaning is intended: 青空 (blue sky) points upward, while 空っぽ (completely empty) describes an empty container.
空 has two main readings. Read it as そら (sora) when it stands alone meaning ‘sky,’ and as クウ (kuu) in compounds such as 空気 (kuuki, air) and 空港 (kuukou, airport). For the ’empty’ sense, you will also see から (kara), as in 空っぽ (karappo, completely empty), and the verb 空く (aku, to become empty or vacant).
Reading
On’yomi: クウ (kuu)
Kun’yomi: そら (sora), あ-く (a-ku), から (kara)
Basic Information
| Kanji | 空 |
|---|---|
| Meaning | sky, empty, void |
| Stroke Count | 8 |
| JLPT Level | N5 |
How to Understand This Kanji
空 carries two distinct common meanings: 空 (そら) = sky, and 空 (から/あ-) = empty. Context determines the intended meaning. In compounds, 空 often means ‘air’ (空気) or relates to aviation (空港, 空軍).
Common Words
- 空（そら / sora） — sky
- 空港（くうこう / kūkō） — airport
- 空気（くうき / kūki） — air, atmosphere
- 青空（あおぞら / aozora） — blue sky
- 空っぽ（からっぽ / karappo） — completely empty
- 空き（あき / aki） — vacancy, empty space, availability
Example Sentences
-
今日は空が青いですね。
きょうはそらがあおいですね。 / Kyō wa sora ga aoi desu ne.
The sky is blue today, isn’t it?
-
空港まで車で行きます。
くうこうまでくるまでいきます。 / Kūkō made kuruma de ikimasu.
I will go to the airport by car.
-
新鮮な空気を吸いましょう。
しんせんなくうきをすいましょう。 / Shinsen na kūki o suimashō.
Let’s breathe fresh air.
When Learners Usually See This Kanji
空 appears in very common words: 空港 (airport), 空気 (air), and 青空 (blue sky). The two meanings — sky and empty — come from the same root idea of open, vast space. Both readings are N5 level.
Summary
空 means both ‘sky’ and ’empty,’ appearing in important everyday words like 空港 (airport) and 空気 (air).