〜おき

〜おき indicates regular intervals. Attached to a number + counter, it means 'every X' or 'at intervals of X.'

PATTERN:
[number + counter] + おきに

EXAMPLES:

• 一日(いちにち)おき: every other day (with one day in between)
• 一週間(いっしゅうかん)おき: every other week
• 5分(ふん)おき: every 5 minutes
• 3メートルおき: every 3 meters

IMPORTANT NUANCE:
With small numbers, おき means 'with X in between,' so 一日(いちにち)おき = every other day (not every day). For 'every day,' use 毎日(まいにち). With larger numbers, the distinction is less important: 10分(ふん)おき and 10分(ふん)ごと are nearly interchangeable.

SIMILAR SUFFIX:

• 〜ごとに: every ~ (emphasizes repetition at each interval, e.g., 一日(いちにち)ごとに = every single day)