What does 速 mean in Japanese?
速 means fast or speed. The most important learning point for this kanji is the homophone 早い (hayai), which also means fast. Both are read はやい, but 速い refers to speed of motion while 早い refers to early in time. Mixing these up is one of the most common mistakes at N4.
速 appears in Japanese train-related and transport words such as 快速 (kaisoku, rapid service), 速度 (sokudo, speed), and 高速 (kousoku, high speed / expressway). Recognising 速 in these contexts is a practical reading skill.
Reading
On’yomi: ソク (soku)
Kun’yomi: はや-い (haya-i), はや-める (haya-meru), はや-まる (haya-maru)
Basic Information
| Kanji | 速 |
|---|---|
| Meaning | fast, speed |
| Stroke Count | 10 |
| JLPT Level | N4 |
How to Understand This Kanji
速い (hayai, fast) describes speed: 速い車 (a fast car), 話すのが速い (fast at speaking). 早い (hayai, early) describes time: 早い時間 (an early time), 朝早く起きる (wake up early in the morning). In kanji, the distinction is clear: 速 for speed, 早 for earliness. In hiragana or spoken Japanese alone, context must carry the distinction. 速める (hayameru) means to speed up; 速まる (hayamaru) means to become faster.
Common Words
- 速い（はやい / hayai） — fast, quick (speed)
- 速度（そくど / sokudo） — speed, velocity
- 高速（こうそく / kousoku） — high speed; expressway
- 快速（かいそく / kaisoku） — rapid (train service)
- 速達（そくたつ / sokutatsu） — express mail, special delivery
- 速める（はやめる / hayameru） — to speed up, to quicken
Example Sentences
-
この電車は速いです。
このでんしゃははやいです。 / Kono densha wa hayai desu.
This train is fast.
-
快速に乗れば10分で着きます。
かいそくにのればじゅっぷんでつきます。 / Kaisoku ni noreba juppun de tsukimasu.
If you take the rapid train, you will arrive in ten minutes.
-
話すスピードを速めてください。
はなすスピードをはやめてください。 / Hanasu supiido o hayamete kudasai.
Please speak faster.
When Learners Usually See This Kanji
速い vs 早い is the core learning point for this kanji. Both are written はやい and sound identical in speech. The rule is: 速い (速, speed) = rate of motion; 早い (早, early) = time. 速く走る (run fast) — about speed. 早く起きる (wake up early) — about time. 走るのが速い (fast at running) vs 朝が早い (early in the morning). When writing in kanji, always check which meaning you intend.
On train signs, a common pattern is that 普通 / 各駅停車 stops at every station, while 快速 skips some stations. Other service names such as 急行 and 特急 vary by railway company and line. Knowing 快速 is especially useful for commuting on Japan’s major urban lines.
高速道路 (kousoku douro, expressway / highway) = 高 (high) + 速 (speed) + 道路 (road). Often shortened to 高速 in conversation: 高速で来た (I came by expressway). 速達 (sokutatsu, express mail / special delivery) appears on Japanese post office forms.
Summary
速 means fast or speed (of motion), with 速い the key adjective. The essential learning point is the 速い vs 早い homophone distinction: 速い for speed, 早い for time.