godan verb (-ku), intransitive verb
be effective; take effect; work
Used for medicine, treatments, measures, and abstract effects. Often with 薬, 治療, 方法, etc. Typically written 効く.
See also: 薬が効く
この薬はよく効く。
This medicine works well.
His advice was effective.
godan verb (-ku), intransitive verb
function well; work (senses/body)
Only when written 利く
Describes bodily senses, faculties, or functions working properly. Common with 目, 耳, 鼻, 口, 頭, etc. Usually written 利く.
See also: 目が利く
彼は目が利くから、いい品を見つける。
He has a good eye, so he finds good items.
風邪で鼻が利かない。
My nose doesn't work because of a cold.
godan verb (-ku), intransitive verb
be possible; be able to use
Only when written 利く
Used in set phrases like 割引が利く (discount applies), 融通が利く (flexible), 無理が利く (can push oneself). Indicates that a condition or allowance is in effect. Usually written 利く.
See also: 割引が効く
この店では学生割引が利く。
A student discount applies at this store.
彼は融通が利かない。
He is inflexible.
godan verb (-ku), transitive verb
taste (alcohol); try (alcohol)
Transitive use meaning to taste or try alcohol. Often used in the form 酒を利く. Less common than 味見する or 試飲する in everyday speech.
See also: 聞く
彼は酒を利くのが趣味だ。
His hobby is tasting sake.