We Japanese often say that the kanji 早 is for "early" and 速 for "fast"
and claim we write that way, but actually we don't.
我们日本人经常说, <早>是和early对应的, <速>是和fast对应的 , 而且说我们用这个方式写文,
但是说实话我们这样不写
e.g, "Do it fast(*)" in English, "快点" in Chinese, but "早くしろ” in Japanese.
(* Do it quickly, Make it snappy)
It is not as clearly separated as "fast vs early" in English or "快 vs 早" in Chinese
I should say this is one of our illogical, confused uses of kanji.
e.g. we say 我们快走吧 as ”早く行かなきゃ”
I suppose we actually write in the following way..
- early - 早(い)
- fast/quick(people) - 早(い)
- faster than others (people) - 速(い)
- fast(things) - 速(い)
***1:early - 早(い)
早寝早起き、
早婚
早春(early in the spring)
朝早い。
早メシ ( e.g, have lunch before noon)
朝早く出社する。
お早うございます。
明日は、朝、仕事が早い(have to work earlier in the morning)
*** fast(people) - 早(い)
早歩き(walk fast)
早くしろ (" you are doing slower than normal. Do it quickly". )
早く!(Hurry up)
早く来て(Come quick)
(何もたもたしてるんだ)早く来い!
早食い(eating fast)
早口(speak fast)
**** faster than than ordinary people (people) - 速(い)
足が速い(run fast <faster than usual people> )
歩くのが速い(walk faster <than ordinary people> )
速記(can write faster <than ordinary people> )
返事が速い(respond quicker <than ordinary people> )
頭の回転が速い(smarter <than ordinary people>
仕事が速い(faster <than ordinary people>)
速読(real faster <than ordinary people>)
**** fast(things, coception) ----> 速い
飛行機の方がクルマより速い(※ 飛行機の方がクルマより早く着く)
速く乾く。速乾タイプ
車輪が速く回る。高速回転。
スマホを速くする。
歩く速さ
読む速さ
*** exception
- 早食いコンテスト (Some people think 速食いコンテスト is better. I understand them)
because 早食いコンテスト is a "食べる速さを競うコンテスト”
like 陸上競技 is a ”走る速さを競うコンテスト”
- 速度を早める。
***
仕事が速い、仕事が早い。Seaching it on Google, you will find both.
*** Courpus
【早くしろ】
https://www.google.com/search?nfpr=1&q=%E6%97%A9%E3%81%8F%E3%81%97%E3%82%8D&spell=1&sa=X&ved=0ahUKEwiH4fbT8-HlAhUG-2EKHTnpAFEQBQguKAA&biw=1300&bih=908