English gets by with one small word for conditions — if — plus a second, when, for timing. Japanese has four conditional markers, and choosing between them is not a matter of style: each encodes a genuinely different logic about how the second event relates to the first. This is one of the real mountains of intermediate Japanese, and the reason is exactly that English never forced you to notice the differences. Where you thought there was one idea ("if"), Japanese sees four. This page is the map: it lays out と, ば, たら, なら side by side so you can see the whole territory before you study each one in depth.
The one-line summary
| Marker | Core logic | English feel |
|---|---|---|
| と | automatic, inevitable result | "whenever you…, (naturally)…" |
| ば | provisional / hypothetical condition | "if…, (then)…" / "if only…" |
| たら | general "if / when," flexible workhorse | "if / when…, then…" |
| なら | premised on a just-raised topic | "if it's the case that…" / "if you're going to…" |
These four are not free variants. Swapping one for another either changes the meaning or produces something a native speaker would never say. The rest of this page walks each one, and the dedicated comparison page tables the differences case by case.
と — the automatic result
と says: whenever A happens, B follows — reliably, automatically, like clockwork. The result is not a choice; it is an inevitable consequence. This is the conditional of machines, directions, natural law, math, and habits. Form it with the dictionary form (or ない form) + と.
このボタンを押すと、電気がつく。
kono botan o osu to, denki ga tsuku
When you press this button, the light comes on.
春になると、桜が咲く。
haru ni naru to, sakura ga saku
When spring comes, the cherry blossoms bloom.
The signature restriction of と is that its main clause must be a non-volitional result — you cannot put a command, request, invitation, or statement of intention after it. That single constraint is what makes と so specific, and it is developed in full on the と page.
ば — the provisional condition
ば sets up a hypothetical or general condition and stresses that the condition itself is what matters — "if A (is true), then B." It is at home with general truths, hypotheticals, and stative results, and it lives inside a whole family of fixed patterns (〜ばいい "should," 〜なければならない "must," 〜ばよかった "should have"). Form it by shifting a godan verb's final -u to -e (行く → 行けば), turning ichidan る into れば (食べる → 食べれば), and い-adjective い into ければ (安い → 安ければ).
もう少し安ければ、買うんだけどな。
mō sukoshi yasukereba, kau n da kedo na
If it were a bit cheaper, I'd buy it.
毎日練習すれば、必ず上手になる。
mainichi renshū sureba, kanarazu jōzu ni naru
If you practice every day, you'll definitely get better.
ば has its own quirk — it resists a same-subject command in the main clause — which is spelled out on the ば page.
たら — the flexible workhorse
たら is the one you can lean on when in doubt. It means both "if" and "when," it works for one-time specific events as easily as general ones, and — unlike と and ば — it happily accepts almost any main clause: commands, requests, invitations, intentions, even a past discovery. Form it from the plain past (た) form + ら: 行った → 行ったら, 食べた → 食べたら, 安かった → 安かったら.
駅に着いたら、電話するね。
eki ni tsuitara, denwa suru ne
When I get to the station, I'll call you.
もし雨が降ったら、試合は中止です。
moshi ame ga futtara, shiai wa chūshi desu
If it rains, the match is cancelled.
Because it is so tolerant, たら is the workhorse of daily conversation — and precisely why learners overuse it and never develop a feel for the other three. The たら page covers its full range, including the special "and then I discovered…" past use.
なら — premised on what was just raised
なら is the odd one out. It does not condition on an event; it conditions on a topic that has just come up — usually something the other person just said or that is otherwise given in context. "If (as you say / as is the case) A, then B." It attaches straight to a noun or plain form: 行くなら, 学生なら, 安いなら.
京都に行くなら、この地図を持っていって。
kyōto ni iku nara, kono chizu o motte itte
If you're going to Kyoto, take this map with you.
そんなに疲れているなら、今日は休んだら？
sonna ni tsukarete iru nara, kyō wa yasundara
If you're that tired, why not take today off?
The tell for なら is that the condition comes from the conversation, not from the timeline. In 京都に行くなら, you are responding to the fact that your listener has announced a trip to Kyoto — you are not saying "when you go." That contextual, topic-taking role is unique among the four.
Ordering in time: a hidden divider
One structural fact cuts across all four and helps you choose. With と, ば, たら, the condition (clause 1) generally happens before the result (clause 2) — press then it lights up. なら reverses this option: the main clause can happen before the topic-clause event. 行くなら切符を買っておいて ("if you're going, buy the ticket beforehand") — you buy the ticket before you go. No other conditional allows that, and it is a strong signal that なら is the right choice.
お酒を飲むなら、車を運転してはいけない。
o-sake o nomu nara, kuruma o unten shite wa ikenai
If you're going to drink, you mustn't drive. (the not-driving covers before and after the drinking)
Formation at a glance
| 行く (godan) | 食べる (ichidan) | 安い (i-adj) | 学生 (noun) | |
|---|---|---|---|---|
| と | 行くと | 食べると | 安いと | 学生だと |
| ば | 行けば | 食べれば | 安ければ | 学生なら(ば) |
| たら | 行ったら | 食べたら | 安かったら | 学生だったら |
| なら | 行くなら | 食べるなら | 安いなら | 学生なら |
Common mistakes
❌ 駅に着くと、電話してください。
eki ni tsuku to, denwa shite kudasai
Incorrect — と cannot take a request in the main clause. Use たら.
✅ 駅に着いたら、電話してください。
eki ni tsuitara, denwa shite kudasai
When you arrive at the station, please call.
Defaulting to a single conditional — usually たら — for every "if" is understandable, but it flattens the meaning. The reverse error is just as common: using と (with its automatic-result logic) where you need to give an instruction.
❌ 京都に行ったら、この地図を持っていって。
kyōto ni ittara, kono chizu o motte itte
Odd here — this says 'once you've arrived in Kyoto, take this map,' but you want the map for the trip itself. Use なら.
✅ 京都に行くなら、この地図を持っていって。
kyōto ni iku nara, kono chizu o motte itte
If you're going to Kyoto, take this map (with you).
❌ 安いと、買います。
yasui to, kaimasu
Marginal — と suggests an automatic law, but buying is a volitional decision. Use ば or たら.
✅ 安ければ、買います。
yasukereba, kaimasu
If it's cheap, I'll buy it.
❌ もし時間があると、手伝います。
moshi jikan ga aru to, tetsudaimasu
Incorrect — 'if I have time' is a hypothetical with a volitional result, not an automatic law. Use ば or たら.
✅ もし時間があれば、手伝います。
moshi jikan ga areba, tetsudaimasu
If I have time, I'll help.
Key takeaways
- Japanese splits English "if / when" across four markers, each with its own logic — they are not interchangeable.
- と = automatic, inevitable result (no command/request/intention in the main clause).
- ば = provisional / hypothetical condition; general truths and fixed patterns.
- たら = flexible "if / when" workhorse; accepts almost any main clause.
- なら = conditions on a just-raised topic, and uniquely lets the main clause precede in time.
- When unsure, sort by the result: automatic → と, hypothetical → ば, specific "then do X" → たら, "if that's the case" → なら.
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Start learning Japanese→Related Topics
- と: Natural ConsequenceN4 — The conditional と for automatic, inevitable, and habitual results — directions, machines, and nature — and its signature ban on commands, requests, and intentions in the main clause.
- ば: Provisional ConditionN4 — The provisional conditional ば — how to form it across all verb and adjective classes, why it favors general truths and stative results, the ば〜ほど pattern, and its restriction on same-subject commands.
- たら: The Versatile If/WhenN4 — How to form and use 〜たら, the most flexible Japanese conditional, which covers both 'if' and 'when' and freely allows requests, commands, and invitations in the main clause.
- と / ば / たら / なら ComparedN3 — The decision guide English learners need most — how Japanese splits the single English 'if' into four conditionals, chosen by the main clause and by where the condition comes from.
- Untangling the Conditionals (と・ば・たら・なら)N3 — A study path through Japanese's four 'if/when' forms — と, ば, たら, なら — sequenced as a decision guide: learn each form, learn the diagnostic that picks between them, then watch them work in real annotated texts.