ちゃんと

This etymology is hypothetical. Possibly some kind of sound shift from 順当 (juntō, “properly, in a smooth way”).

/dʑɯntoː/ → /dʑɯnto/ → /tɕanto/

• (Tokyo) ちゃんと [chàńtó] (Heiban – [0])[1][2]
• IPA^(key): [t͡ɕã̠nto̞]

ちゃんと • (chanto) 

1. as one should

   ちゃんとしてね

   chanto shite ne

   make sure you do a good job

   ちゃんと覚(おぼ)えてね

   chanto oboete ne

   don't forget; make sure to remember

   ちゃんとやれよ

   chanto yare yo

   hey! take it seriously

   ちゃんと鍵(かぎ)かけたか

   chanto kagi kaketa ka

   did you remember to lock the door

   朝(あさ)ごはんちゃんと食(た)べたか

   asagohan chanto tabeta ka

   did you remember to eat breakfast; have you eaten breakfast yet [like you should]

   宿(しゅく)題(だい)はちゃんとやりましたか

   shukudai wa chanto yarimashita ka

   did you do your homework

2. properly
   • 1939, Osamu Dazai, Joseito [Schoolgirl]‎:

     ジャピイを可(か)愛(わい)がっていると、カアは、傍(そば)で泣(な)きそうな顔(かお)をしているのをちゃんと知(し)っている。

     Japī o kawaigatte iru to, Kā wa, soba de nakisō na kao o shite iru no o chanto shitte iru.

     I am perfectly aware that when I dote on Japī, Kā is by the side making a face that looks like she might cry.

3. always, regularly, punctually

ちゃんとする • (chanto suru) suru (stem ちゃんとし (chanto suru shi), past ちゃんとした (chanto suru shita))

1. be proper, exact, right

   その行(こう)動(どう)にはちゃんとした理(り)由(ゆう)がある

   sono kōdō ni wa chanto shita riyū ga aru

   there is a proper reason to [his, her, their] actions

   ちゃんとした道(どう)具(ぐ)で作(つく)る

   chanto shita dōgu de tsukuru

   create using the right equipment