(くち)()ける

くちをあける
expression (verb phrase)
to open one's mouth; to open (a container)
Conjugation
AffirmativeNegative
Present(くち)()ける(くち)()けらない
Present polite(くち)()けります(くち)()けりません
Past(くち)()けった(くち)()けらなかった
Past polite(くち)()けりました(くち)()けりませんでした
て form(くち)()けって(くち)()けらなくて
ている present(くち)()けっている(くち)()けっていない
ている polite(くち)()けっています(くち)()けっていません
ている past(くち)()けっていた(くち)()けっていなかった
ている past polite(くち)()けっていました(くち)()けっていませんでした
Conditional ば(くち)()ければ(くち)()けらなければ
Conditional たら(くち)()けったら(くち)()けらなかったら
Volitional(くち)()けろう
Volitional polite(くち)()けりましょう
Potential(くち)()けれる(くち)()けれない
Passive(くち)()けられる(くち)()けられない
Causative(くち)()けらせる(くち)()けらせない
Imperative(くち)()けれ(くち)()けるな
1. to open one's mouth (to speak, yawn, or receive food, medicine, or a dental exam)
The basic, literal sense: to physically open the mouth. Commonly heard at the dentist ((くち)(おお)きく()けてください), when feeding a baby or an animal, or when describing someone yawning or singing. Note: for the sense 'to start talking; to speak up', Japanese usually prefers (くち)(ひら)く with the reading ひらく.
(くち)()けてください。
Please open your mouth.
(あか)ちゃんが(くち)()けてあくびをした。
The baby opened its mouth and yawned.
歯医者(はいしゃ)さんに「もう(すこ)(おお)きく(くち)()けて」と()われて、必死(ひっし)であごを(ひろ)げた。
When the dentist said 'Please open your mouth a little wider,' I spread my jaws open for all I was worth.
2. to open (a bottle, package, or other container); to unseal
By extension from the 'mouth' metaphor for openings: to remove the cap or seal of a bottle, jar, bag, or similar container, often for the first time. Common with foods, drinks, cosmetics, and medicines.
ワインの(くち)()ける。
To open a bottle of wine.
(あたら)しい醤油(しょうゆ)(くち)()けたら、(かお)りが()った。
When I opened the new bottle of soy sauce, the aroma wafted up.
土産(みやげ)にもらったジャムの(びん)(くち)()けたら、(あま)(かお)りが部屋(へや)いっぱいに(ひろ)がった。
When I opened the jar of jam that I had received as a souvenir, a sweet aroma filled the entire room.

The construction is noun (くち) + を + verb ()ける. (くち) here refers literally to the mouth (sense 1) or to the opening/mouth of a container (sense 2); ()ける is the transitive verb 'to open'.

USAGE:

  • Sense 1 is nearly always concrete and physical. The metaphorical 'open one's mouth = start speaking' sense is normally carried by (くち)(ひら)く (same kanji, but read ひらく). Beginning learners often conflate them.
  • For the intransitive counterpart (a mouth/container opens by itself or is open), use (くち)()く or the state form (くち)()いている.
  • In sense 2, (くち)()る is a near-synonym, especially for unsealing a new package or bottle for the very first time.

COMMON COLLOCATIONS:

  • (くち)(おお)きく()ける: to open one's mouth wide
  • (くち)()けて(わら)う: to open one's mouth and laugh
  • あくびをして(くち)()ける: to open one's mouth in a yawn
  • ワインの(くち)()ける: to open a bottle of wine
  • (びん)(くち)()ける: to open the mouth of a bottle
  • (ふくろ)(くち)()ける: to open the mouth of a bag

SIMILAR WORDS:

  • (くち)(ひら)く: to open one's mouth (and speak); to break one's silence — figurative use, focused on speech.
  • (くち)()る: to be the first to speak; also to unseal a new container — overlaps with sense 2 when referring to opening something for the first time.
  • (くち)()じる / ()める: to close one's mouth — the antonym.
  • ()ける: to open — the general transitive verb; combines freely with many objects (door, window, box).