Vocabulary
口を開く
くちをひらく
to open one's mouth (to talk); to (start to) tell
expression
verb
Example sentences
彼（かれ）は口（くち）を開（ひら）くと必（かなら）ず何（なに）かしら不満（ふまん）を言（い）う。
He never opens his mouth without complaining about something.
そしてついに口（くち）を開（あ）いた。
Then, finally, she opened her mouth.
彼女（かのじょ）はあまりしゃべらないが、いったん口（くち）を開（ひら）くと弁（べん）が立（た）つ。
She doesn't talk much, but once she does speak she is eloquent.