N4 — outside your level filter
per — how many times, or how much, fits inside one period
英会話のレッスン、週に一回だけ受けてるんだ。
eikaiwa no ressun, shuu ni ikkai dake uketeru n da.
I only take an English conversation lesson once a week. casual
この薬は一日に三回、食後に飲んでください。
kono kusuri wa ichinichi ni sankai, shokugo ni nonde kudasai.
Take this medicine three times a day, after meals. neutral
〜に〜回
〜に〜かいni ... kaiN4neutral