早い vs 速い
JLPT N5 vocabulary · what is the difference?
早い is about time — something happens sooner than expected, or at an early hour. 速い is about speed — something moves or gets done quickly. If "early" fits the English, use 早い; if "fast" fits, use 速い.
When to use each
早い
はやい
Use 早い for position on a clock or calendar: early in the morning, earlier than planned, too soon. It is also the usual spelling in the adverb 早く when you mean "soon" or "hurry up".
今朝は早く起きました。
けさははやくおきました。
I got up early this morning.
帰るにはまだ早いですよ。
かえるにはまだはやいですよ。
It's still too early to go home.
速い
はやい
Use 速い for rate of movement or work: trains, runners, typing, an internet connection. Its opposite is 遅い in the sense of slow, not late.
この電車は速いです。
このでんしゃははやいです。
This train is fast.
兄は走るのが速いです。
あにははしるのがはやいです。
My older brother is a fast runner.
Sentences where only one works
会議を始めるのはまだ早いです。
かいぎをはじめるのはまだはやいです。
It's still too early to start the meeting.
Nothing is moving; this is a point in time, so 早い.
新幹線はとても速いです。
しんかんせんはとてもはやいです。
The Shinkansen is very fast.
Pure speed. 早い here would mean the train is running ahead of schedule — a different claim entirely.
もう少し速く歩いてください。
もうすこしはやくあるいてください。
Please walk a bit faster.
You are asking for a higher walking speed, so 速く. 早く歩いてください would push them to set off sooner.
早く来てください。
はやくきてください。
Please come early.
Arriving sooner is timing, so this is 早く — the standard spelling when you are hurrying someone along.
Common mistakes
この車は早いです。
この車は速いです。
Meant as "this car is fast", it reads as "this car is early". It rarely blocks understanding, but it is visibly the wrong kanji.
速く寝てください。
早く寝てください。
The over-correction. Going to bed sooner is a matter of timing, so 早く. Learners who have just met 速い start using it for everything.
Frequently asked questions
Which one do I use for 早く when telling someone to hurry?
早く. Hurrying someone is about doing it sooner, so the time kanji is standard — 早くして, 早く行こう. 速く appears only when you literally want more speed, as in 速く走れ.
What about 仕事が早い?
This one genuinely varies. 仕事が早い (finishes sooner) is the more common spelling for someone who works quickly, but 仕事が速い also appears and is not an error. Where the sense sits between timing and speed, writers disagree.
Can I just write はやい in kana?
Yes, and it is a reasonable way out when the sense is mixed. In formal writing pick a kanji; in casual messages kana is unremarkable.