Take one number — say, thirty minutes — and Japanese lets you say three completely different things about it without changing the number at all. Attach は and it becomes a floor: "at least thirty minutes." Attach も and it becomes a shock: "a whole thirty minutes." Attach しか…ない and it becomes a shortfall: "only thirty minutes." English needs an entire phrase for each of these; Japanese does it with a single particle riding on the quantity. Learning this system means learning to hear the speaker's attitude toward an amount, which is information a bare translation usually throws away.
All three attach after the number + counter phrase, which normally sits right before the verb (see counter position). Start from the neutral baseline — no particle on the quantity — and each particle adds a layer of evaluation on top.
駅まで歩いて三十分かかる。
eki made aruite sanjuppun kakaru
It's a thirty-minute walk to the station. (neutral — just the fact)
数量 + は — "at least," a confident floor
Putting は on a quantity marks it as a minimum you are sure of: it will be at least this much, possibly more. The speaker is committing to a lower bound.
駅まで歩いて三十分はかかるよ。
eki made aruite sanjuppun wa kakaru yo
It's a good thirty minutes on foot to the station — at least.
この修理には一時間はかかると思う。
kono shūri ni wa ichijikan wa kakaru to omou
I think this repair will take at least an hour.
新しいパソコンなら、十万円はするだろう。
atarashii pasokon nara, jūman'en wa suru darō
A new computer will cost at least 100,000 yen, I'd say.
This は is the topic/contrast は in its scalar-contrast role: "as for this much, it's guaranteed." The nuance is "don't expect less than this." It pairs naturally with かかる (take/cost), する (cost), ある (there is), and other measured predicates.
数量 + も — "as many/much as," a surprised large amount
も on a quantity marks the number as surprisingly large — more than expected. English reaches for "as many as," "as much as," "a whole," or an exclamation mark; も packs all of that into one syllable.
えっ、駅まで三十分もかかるの?
e', eki made sanjuppun mo kakaru no?
What — it takes a whole thirty minutes to the station?!
昨日のパーティーには十人も来た。
kinō no pātī ni wa jūnin mo kita
As many as ten people came to yesterday's party.
同じ問題で三回も失敗してしまった。
onaji mondai de sankai mo shippai shite shimatta
I failed at the same problem three whole times.
彼は一晩でビールを五本も飲んだ。
kare wa hitoban de bīru o gohon mo nonda
He drank as many as five beers in one evening.
The speaker's stance is "that's a lot!" — mild astonishment, sometimes disapproval. This is the quantity use of emphatic も. The same 三回 that is neutral in 三回失敗した becomes a pointed "three times, can you believe it" in 三回も失敗した.
The flip side: 一 + counter + も…ない — "not even one"
With a negative predicate, 数量+も flips to "not even": the smallest quantity, plus も, plus ない = "not a single one." This is the mirror image of the "surprisingly many" use — surprisingly few, all the way down to zero.
時間がなくて、朝から水を一杯も飲んでいない。
jikan ga nakute, asa kara mizu o ippai mo nonde inai
I've been so busy I haven't had even a single glass of water since morning.
約束したのに、一人も来なかった。
yakusoku shita no ni, hitori mo konakatta
Even though they promised, not a single person showed up.
数量 + しか…ない — "only," a disappointing shortfall
しか always pairs with a negative predicate, and on a quantity it means "only / no more than," with a flavor of insufficiency — this is less than you'd want or need.
急ごう、あと三十分しかない。
isogō, ato sanjuppun shika nai
Let's hurry — we've only got thirty minutes left.
財布に千円しか入っていない。
saifu ni sen'en shika haitte inai
I've only got 1,000 yen in my wallet.
この漢字は一度しか習っていないから、まだ書けない。
kono kanji wa ichido shika naratte inai kara, mada kakenai
I've only studied this kanji once, so I still can't write it.
The grammatical hook: しか is bound to a negative verb, so the sentence looks negative but reads positive-with-limit. 千円しかない = literally "there isn't (anything) but 1,000 yen" = "I have only 1,000 yen." That obligatory ない is exactly what learners forget (full treatment on しか…ない).
The whole system on one number
The compact power of this system is easiest to feel side by side. Same amount, three attitudes:
| Sentence | Particle | Speaker's attitude |
|---|---|---|
| 三十分かかる | — (bare) | neutral fact: it takes 30 min |
| 三十分はかかる | は | floor: at least 30 min, maybe more |
| 三十分もかかる | も | surprise: a whole 30 min! |
| 三十分しかない | しか…ない | shortfall: only 30 min, not enough |
しか vs だけ — two kinds of "only"
English "only" splits in Japanese. だけ is the neutral limiter ("just this, and that's fine"); しか…ない adds the sense of shortfall or regret ("only this, which isn't enough"). Both can be grammatical for the same amount; they simply feel different.
千円だけ持っている。
sen'en dake motte iru
I have just 1,000 yen. (neutral — that's the amount)
千円しか持っていない。
sen'en shika motte inai
I only have 1,000 yen. (regretful — that's not much)
If you want to complain that an amount is too small, use しか…ない; if you're just stating the quantity, だけ is cleaner.
Common Mistakes
❌ 十人も来た =「ちょうど10人来た」と訳す。
Incorrect — it means 'as many as ten came,' with surprise, not a plain 'ten came.'
✅ 十人も来た =「10人 も 来た(そんなに!)」。
jūnin mo kita
As many as ten people came!
The commonest reading error: flattening 数量+も into a neutral count and losing the "that's a lot" attitude. も is never decorative here.
❌ 一時間はかかる =「ちょうど1時間かかる」。
Incorrect — は marks a minimum, not an exact amount.
✅ 一時間はかかる =「最低でも1時間はかかる」。
ichijikan wa kakaru = saitei demo ichijikan wa kakaru
It'll take at least an hour.
❌ 財布に千円しかある。
Incorrect — しか demands a negative predicate.
✅ 財布に千円しかない。
saifu ni sen'en shika nai
I only have 1,000 yen.
しか cannot live with an affirmative verb. 千円しかある is ungrammatical; it must be 千円しかない.
❌ 五分もない =「たった5分だ」と言いたい時に使う。
Careful — 五分もない means 'less than five minutes / not even five,' not 'only five.'
✅ 五分しかない = ちょうど5分(足りない)。/ 五分もない = 5分未満。
gofun shika nai / gofun mo nai
only five minutes / not even five minutes
Learners blur 五分しかない ("only five minutes," roughly five) with 五分もない ("not even five minutes," under five). The も…ない frame subtracts below the number; しか…ない sits at it.
❌ 千円しか持っている。
Incorrect — same shika-plus-affirmative error, very frequent.
✅ 千円しか持っていない。
sen'en shika motte inai
I only have 1,000 yen.
Key Takeaways
- 数量 + は = "at least" — a confident floor (千円はかかる = at least 1,000 yen).
- 数量 + も = "as many/much as" — surprise at a large amount (十人も来た = as many as ten came); with a negative and the smallest unit, "not even one" (一人も来なかった).
- 数量 + しか…ない = "only" — a disappointing shortfall, with an obligatory negative verb (千円しかない).
- The same number carries floor / surplus / shortfall depending only on the particle — a compact attitude system English spells out in full phrases.
- Prefer だけ over しか when you mean a plain "just," with no sense of shortfall.
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Start learning Japanese→Related Topics
- も: Emphasis — 'Even', 'As Many As'N4 — How も after a quantity means 'as much/many as' (a surprised 'that's a lot'), how minimal-quantity も plus a negative means 'not even one', and how 何も/誰も build 'nothing/nobody'.
- しか…ない: Only (with Negative)N4 — How しか always pairs with a negative verb to mean 'only / nothing but' — a negative form carrying a positive 'I have only X' meaning, coloured with 'and that's not much' — plus how it replaces は/が/を, stacks on other particles, and forms the 'no choice but' idiom.
- Where the Number Goes: Floating QuantifiersN4 — The syntax of number-plus-counter phrases — why the natural spoken order floats the quantifier after the noun and particle (ビールを三本飲んだ) rather than before the noun, and when the heavier 三本のビール form is right.
- は: The Topic MarkerN5 — How は (written ha, read wa) sets the topic of a sentence — the frame 'as for X' that the rest of the sentence comments on — and why topic is not the same as subject.
- だけ: Only, JustN4 — How だけ marks a neutral limit ('only, just') with a positive verb, its combinations だけで, だけでなく and だけの, where it sits relative to particles, and how it differs in feeling from しか…ない.