ごとに and おきに: Intervals and 'Every' | Japanese Grammar

English collapses two different ideas into one word. "Every three days" and "every other day" both use every, and "every other day" is a phrase you memorize rather than build. Japanese pulls these apart cleanly with two suffixes: ごとに counts the recurrence unit itself, while おきに counts the gap between events. Once you see that one of them includes the interval and the other skips it, the notorious exam trap — is 一日おきに daily or every other day? — solves itself.

Both attach to a quantity (number + counter) and turn it into a frequency adverb, usually with に. The whole phrase sits before the verb, like any other adverb of time (see に and time expressions).

ごとに — "every / each," counting the unit

〜ごとに (毎（ごと）に in older writing, now written 〜ごとに) means the interval you name is the recurrence period. 三日（みっか）ごとに = the cycle is three days long, so the event lands on day 1, day 4, day 7, and so on.

この薬は六時間ごとに飲んでください。

kono kusuri wa rokujikan goto ni nonde kudasai

Take this medicine every six hours.

バスは十分ごとに出ます。

basu wa juppun goto ni demasu

The buses leave every ten minutes.

オリンピックは四年ごとに開かれる。

orinpikku wa yonen goto ni hirakareru

The Olympics are held every four years.

The unit you attach ごとに to is simply repeated. 六時間ごとに = a six-hour cycle; the next dose is six hours after the last. There is no skipping — this is the intuitive, "textbook" every.

ごとに after verbs and nouns — "each time / by each"

ごとに has a second life that おきに does not share: it attaches to a plain-form verb or a bare noun to mean "each time X" or "one by one, per X." This is the distributive sense.

会うごとに彼女はきれいになっていく。

au goto ni kanojo wa kirei ni natte iku

Every time we meet, she's more beautiful than before.

年を取るごとに、一年が過ぎるのが早く感じる。

toshi o toru goto ni, ichinen ga sugiru no ga hayaku kanjiru

With each passing year, a year seems to go by faster.

この調査は国ごとに結果が大きく違う。

kono chōsa wa kuni goto ni kekka ga ōkiku chigau

In this survey the results differ greatly from country to country.

Here ごとに means "with each occurrence of" (会うごとに, 年を取るごとに) or "broken down by" (国ごとに = per country, 家ごとに = house by house). You cannot substitute おきに in any of these — おきに only ever attaches to a countable quantity.

💡

If the meaning is "each time something happens" or "one per unit," it is always ごとに. おきに never attaches to a verb: 会うごとに ✓ but 会うおきに ✗.

おきに — "at intervals of / every other," counting the gap

〜おきに (置（お）きに, "leaving X aside") names the amount left as a gap between events, not the cycle. This one extra step of logic is the whole difference — and the whole difficulty.

この薬は一日おきに飲みます。

kono kusuri wa ichinichi oki ni nomimasu

I take this medicine every other day.

祖母の家には一日おきに通っている。

sobo no ie ni wa ichinichi oki ni kayotte iru

I go to my grandmother's house every other day.

一日おきに means one whole day is left empty between visits: you go Monday, skip Tuesday, go Wednesday. The event recurs every second day. This "every other day" reading of 一日おきに is universal — no native speaker disputes it, and it is the single most important fact on this page.

The same skip logic runs across counters for people, houses, and distance:

このプリントは一人おきに配ってください。

kono purinto wa hitori oki ni kubatte kudasai

Hand out these sheets to every other person.

街路樹は五メートルおきに植えられている。

gairoju wa go mētoru oki ni uerarete iru

The street trees are planted at five-meter intervals.

The counting trap: ごとに includes, おきに skips

Line the two up on the same number and the split is stark:

Expression	Literal logic	Events fall on…	Natural English
一日ごとに	1-day cycle	every day	every day (= 毎日)
一日おきに	1 day left as a gap	day 1, 3, 5…	every other day
一週間ごとに	1-week cycle	every week	every week (= 毎週)
一週間おきに	1 week left as a gap	week 1, 3, 5…	every other week

二時間ごとに休憩を取りましょう。

nijikan goto ni kyūkei o torimashō

Let's take a break every two hours.

二日おきにジムに通っている。

futsuka oki ni jimu ni kayotte iru

I go to the gym every third day (with two days off in between).

Notice 二日おきに: two full days are skipped, so the gym days are Monday, Thursday, Sunday — a three-day recurrence. This is exactly the arithmetic English speakers get wrong, because "every other" only ever means "skip one" in English and there is no everyday phrase for "skip two."

💡

The reliable mental rule: ごとに = the number is the period (event every N units); おきに = the number is the skip (event every N+1 units). 三日ごとに = every 3rd day; 三日おきに = every 4th day.

An honest caveat: おきに with distance and larger numbers

Two places where careful learners should slow down.

Distance and duration blur the two. With continuous measures — meters, and often minutes used for a schedule — the "gap" and the "cycle" coincide, so 五メートルおきに and 五メートルごとに end up meaning the same thing: a marker every five meters. Likewise, most speakers treat 五分おきに (a bus every five minutes) as identical to 五分ごとに. The skip/include distinction only bites for countable whole units like 日, 週, 月, 年, 人, 軒.

電車は昼間、五分おきに来るから急がなくていいよ。

densha wa hiruma, gofun oki ni kuru kara isoganakute ii yo

During the day the trains come every five minutes, so there's no need to rush.

Bigger おきに numbers are genuinely contested. While 一日おきに is agreed by everyone, native usage actually splits on 三日おきに: the logical reading is "every fourth day" (skip three), but a large minority of speakers use it for "every three days." Japanese language authorities have documented this lack of consensus. There is no clean rule to rescue you here — this is a real fuzzy edge of the language. The practical takeaway: for anything past 一日おき / 一週間おき, careful writers avoid the ambiguity by switching to ごとに, to 隔（かく）〜 (隔日 = every other day, 隔週 = every other week), or to a spelled-out phrase.

Common Mistakes

❌ 薬を一日おきに飲む。(= 毎日のつもりで)

Incorrect if you mean 'daily' — 一日おきに is every OTHER day.

✅ 薬を毎日飲む。/ 薬を一日ごとに飲む。

kusuri o mainichi nomu / kusuri o ichinichi goto ni nomu

I take the medicine every day.

The number-one error: reading 一日おきに as "every day." おき always inserts a skip, so 一日おきに is every second day. For true daily, use 毎日.

❌ 会うおきに好きになる。

Incorrect — おきに cannot attach to a verb.

✅ 会うごとに好きになる。

au goto ni suki ni naru

Every time we meet, I like her more.

The "each time" meaning is ごとに only. おきに attaches solely to a quantity of units, never to a verb or a bare noun.

❌ 三日おきに = 「きっちり3日に一度」と決めつける。

Incorrect to assume it certainly means 'every three days' — logically it is the fourth day, and usage even varies.

✅ 三日ごとに = 3日に一度。三日おきに = 3日空けて4日に一度(揺れあり)。

mikka goto ni = mikka ni ichido; mikka oki ni = mikka akete yokka ni ichido

三日ごとに = once every three days; 三日おきに = leaving three days, once every fourth day (usage varies).

❌ バスは十分ごとです。

Understandable but incomplete — the frequency adverb normally keeps に before a verb.

✅ バスは十分ごとに来ます。

basu wa juppun goto ni kimasu

The buses come every ten minutes.

You may see 〜ごと / 〜おき without に in headlines and captions, but before a verb the full 〜ごとに / 〜おきに is expected in normal writing and speech.

❌ 一列おきに座って、と言われて全部の列に座った。

A real logic slip — 一列おきに means leave every other row empty.

✅ 一列おきに座ってください。(= 一つ飛ばしで)

ichiretsu oki ni suwatte kudasai

Please sit in every other row (leaving one empty between).

Key Takeaways

ごとに = the interval you name is the recurrence period. 三日ごとに = every three days. It also means "each time" on verbs (会うごとに) and "per unit" on nouns (国ごとに).
おきに = the interval you name is the gap that gets skipped. 三日おきに = leave three days, i.e. roughly every fourth day; 一日おきに = every other day.
一日おきに (every other day) vs 一日ごとに (every day) is the confusion to burn in.
With distance and minutes, おきに and ごとに converge; with days/weeks/months/years/people, they truly differ.
Past 一日おき, larger おき numbers are genuinely ambiguous even to natives — reach for ごとに or 隔〜 when clarity matters.

Now practice Japanese

Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.

Start learning Japanese→