expression, i-adjective
Describes a person who cannot speak, either due to a physical condition or extreme emotion. Often used in the phrase 口のきけない状態 (a state of being unable to speak).
彼は生まれつき口のきけない人だ。
He is a person who has been unable to speak since birth.
驚きのあまり口のきけなくなった。
I was so surprised that I became unable to speak.
Means 'taciturn' or 'quiet by nature', not physically unable to speak. 口のきけない implies a lack of ability, while 無口 implies a lack of inclination.
Standard spelling using きく in kana; the most neutral written form.
Uses 利く, which can imply effective functioning; less common but still seen.
Irregular kanji usage; 聞く normally means 'to hear', so this spelling is non-standard and may confuse learners.
Phrase composed of 口 (mouth) + の (possessive particle) + きけない (negative potential form of きく 'to function/be effective'). Literally 'mouth cannot function'.