child's play

English

Patterned after German Kinderspiel, French jeu d'enfant, Italian gioco da bambini, Italian gioco da ragazzi.

child's play (uncountable)

(idiomatic) Something particularly simple or easy.
Compared to my last job, this is child's play.
- 2015 August 18, Robert Frost, The Road Not Taken and Other Poems: (Penguin Classics Deluxe Edition) (Penguin Classics Deluxe Edition)‎, Penguin, →ISBN, OCLC 1155952570, page 51:
  And then he'd crow as if he thought that child's play The only fun he had. I've heard them say, though, They found a way to put a stop to it. He was before my time—I never saw him; But the pen stayed exactly as it was There in the upper chamber in the ell, A sort of catch-all full of attic clutter. […]
Used other than figuratively or idiomatically: the play of a child.

something particularly simple or easy

Chinese:
Cantonese: 兒戲,儿戏 (ji⁴ hei³)
Mandarin: 如同兒戲／如同儿戏 (rútóng'érxì), 很容易的事 (hěn róngyì de shì), 小兒科／小儿科 (zh) (xiǎo'érkē), 兒戲／儿戏 (zh) (érxì)
Min Nan: 兒戲, 儿戏 (jî-hì; lî-hì)
Dutch: kinderspel (nl) n
Esperanto: infana ludo
Finnish: lastenleikki (fi)
French: jeu d'enfant (fr)
German: Kinderspiel (de) n, Spaziergang (de) m
Greek:
Ancient: παιδιή (paidiḗ)
Hungarian: gyerekjáték (hu)
Icelandic: barnaleikur (is) m, auðveldur (is) m, leika sér að, leikur (is) m, innanhandar
Italian: gioco da ragazzi
Japanese: 朝飯前のこと (ja) (あさめしまえのこと, asameshimae-no koto), お茶の子 (ja) (おちゃのこ, o-cha-no ko), 児戯 (ja) (jigi)
Norwegian:
Bokmål: barnemat (no) m
Nynorsk: barnemat m
Plautdietsch: Spälarie f
Polish: dziecinada (pl) f, pikuś (pl) m
Portuguese: brincadeira de criança f
Romanian: joacă de copil f
Russian: игру́шки (ru) f pl (igrúški), се́мечки (ru) n pl (sémečki), пустяки́ (ru) m pl (pustjakí)
Serbo-Croatian: igrarija (sh) f
Spanish: pan comido (es) m, una papa (es) f (Argentina), juego de niños m
Swedish: barnlek (sv) c
Turkish: çocuk oyuncağı (tr)