Japanese conditionals: と, ば, たら and なら explained

English gets by with one word — "if" — and lets context do the rest. Japanese splits the same territory into four grammatical forms: と, ば, たら and なら. Textbooks usually introduce them in four separate chapters, which is exactly why learners end up guessing. They are not four synonyms competing for the same job. Each one encodes a different relationship between the two clauses: automatic consequence, general rule, one specific case, and "given what you just told me". Once you can name those four relationships, choosing the right form stops being a coin flip. This guide gives you the formation rules, the restriction that catches everyone, side-by-side comparisons, and a realistic order to learn them in.

1. Why four forms exist

English "if" is genuinely ambiguous, and we resolve it silently. Compare three sentences: "If you press this button, the door opens." "If it rains tomorrow, I won't go." "If you're going to Japan, Kyoto is worth it." The first is a physical law — press the button and it happens every time. The second is a single uncertain future event. The third isn't really a condition at all; it's a reaction to something the other person just said. Japanese assigns a different form to each of those, which means Japanese sentences carry information that English "if" throws away.

Here is the shortest possible summary, and it will already get you through most conversations: と = automatic, always-true consequence. ば = general or hypothetical condition, with focus on the condition itself. たら = "once/when this specific thing happens", the most flexible of the four. なら = "if it's the case that…", picking up context that already exists. The rest of this guide fills in the detail — but if you only remember one thing, remember that たら is the safe default and と is the one with a hard restriction attached.

2. と — automatic and inevitable

Formation: attach と directly to the plain non-past form. Verbs: 押す → 押すと, 行かない → 行かないと. い-adjectives: 高い → 高いと. な-adjectives and nouns need だ: 静かだと, 学生だと. There is no past-tense version — you never say ×押したと for a conditional.

と says that B follows A automatically, every time. It is the language of machines, maps, natural cycles and habits:

• このボタンを押すと、ドアが開きます。(このボタンを おすと、ドアが ひらきます) — "If/when you press this button, the door opens."
• 春になると、桜が咲きます。(はるに なると、さくらが さきます) — "When spring comes, the cherry trees bloom."
• この道をまっすぐ行くと、駅があります。(このみちを まっすぐ いくと、えきが あります) — "If you go straight along this road, there's the station."
• お酒を飲むと、顔が赤くなります。(おさけを のむと、かおが あかく なります) — "When I drink alcohol, my face goes red."

The restriction — this is the important part. Because と claims the result is automatic, the second clause cannot be something the speaker controls or asks for. No requests, no commands, no invitations, no offers, no statements of personal intention. 春になると花が咲く works perfectly; ×春になると花を見てください does not, because "please look at the flowers" is a request, not an inevitable consequence of spring. Say 春になったら花を見てください instead. The same failure pattern shows up constantly in learner writing:

• ×駅に着くと、電話してください。→ ○ 駅に着いたら、電話してください。(えきに ついたら、でんわして ください) — "Call me when you get to the station."
• ×時間があると、一緒に行きましょう。→ ○ 時間があったら、一緒に行きましょう。(じかんが あったら、いっしょに いきましょう) — "If you have time, let's go together."

There is one very common and very useful exception to the "no volition" feel of と: the fixed pattern 〜ないと meaning "have to". 早く行かないと。(はやく いかないと) literally trails off as "if [I] don't go soon…" and functions as "I'd better get going." It is the casual cousin of なければならない from the next section.

One more use worth recognising early, because novels and diaries are full of it: と with a past-tense main clause marks a discovery. 部屋に入ると、電気がついていた。(へやに はいると、でんきが ついて いた) — "When I entered the room, the light was on." The と-clause stays non-past even though the whole sentence is in the past; the effect is "and then, unexpectedly, I found…".

3. ば — the general, hypothetical condition

Formation is the fiddliest of the four, but it is completely regular. If you already worked through verb conjugation basics, this is one more stem to add:

• Godan (u-verbs): change the final -u to -eba. 行く → 行けば, 話す → 話せば, 待つ → 待てば, 飲む → 飲めば, 買う → 買えば, 帰る → 帰れば.
• Ichidan (ru-verbs): drop る, add れば. 食べる → 食べれば, 見る → 見れば, 起きる → 起きれば.
• Irregulars: する → すれば, 来る (くる) → 来れば (くれば).
• Negatives: drop the final い of ない and add ければ. 行かない → 行かなければ, 食べない → 食べなければ.
• い-adjectives: same pattern — 安い → 安ければ, いい → よければ (note the irregular stem よ-).
• な-adjectives and nouns: in practice people use なら here — 静かなら, 学生なら — though 静かであれば and 学生であれば are the more formal written equivalents.

ば states a general principle or a hypothetical, and it puts the spotlight on the condition: "given this, that follows." 安ければ買います。(やすければ かいます) — "If it's cheap, I'll buy it." 時間があれば、行きます。(じかんが あれば、いきます) — "If I have time, I'll go." 分からなければ、聞いてください。(わからなければ、きいて ください) — "If you don't understand, please ask."

That last example matters, because ば has a softer version of the と restriction. When the ば-clause is stative — an adjective, a negative, ある/いる, or a potential form — a request or suggestion in the main clause is perfectly natural (分からなければ聞いてください, 安ければ買ってください). When the ば-clause is an action verb performed by the same person, a request in the main clause sounds off; ×東京に行けば、電話してください should be 東京に行ったら、電話してください. If you are unsure, たら is always available.

ば also anchors several fixed patterns that are worth memorising as whole units, because you will meet them far more often than you'll build a ば-clause from scratch:

• 〜ば〜ほど — "the more… the more…". 練習すればするほど上手になります。(れんしゅう すれば する ほど じょうずに なります) — "The more you practise, the better you get." 安ければ安いほどいい。(やすければ やすい ほど いい) — "The cheaper the better."
• なければならない / なければいけない — "must, have to". 明日までに出さなければなりません。(あしたまでに ださなければ なりません) — "I have to hand it in by tomorrow." In speech this contracts hard: 出さなきゃ, 行かなきゃ.
• 〜ばよかった — regret. もっと勉強すればよかった。(もっと べんきょう すれば よかった) — "I should have studied more."
• 〜ばいい — advice or a solution. どうすればいいですか。(どう すれば いいですか) — "What should I do?"

4. たら — the flexible one you should learn first

Formation is the easiest of the four: take the plain past form and add ら. That means if you can make the た-form, you already have the conditional. 食べる → 食べた → 食べたら. 行く → 行った → 行ったら. 飲む → 飲んだ → 飲んだら. する → した → したら. 来る → 来た (きた) → 来たら (きたら). Negative: 行かなかった → 行かなかったら. い-adjectives: 高かった → 高かったら. Nouns: 学生だった → 学生だったら. The single most common formation mistake is attaching ら to the dictionary form — ×行くたら. It is always past + ら.

たら covers a single, specific case rather than a general rule, and it carries no restriction on the main clause. Requests, invitations, commands, intentions, past events — all fine. That combination is why it is the workhorse of spoken Japanese and the one beginners should reach for by default:

• 雨が降ったら、行きません。(あめが ふったら、いきません) — "If it rains, I won't go."
• 日本に行ったら、京都に行きたいです。(にほんに いったら、きょうとに いきたいです) — "If/when I go to Japan, I want to visit Kyoto."
• もし宝くじが当たったら、何を買いますか。(もし たからくじが あたったら、なにを かいますか) — "If you won the lottery, what would you buy?" (もし is optional and simply flags the sentence as hypothetical up front.)

The "when/after" use. This is where たら quietly does something the other forms can't. When the first event is certain to happen and only the timing is open, たら means "once / after", not "if":

• 十八歳になったら、車の免許が取れます。(じゅうはっさいに なったら、くるまの めんきょが とれます) — "Once you turn 18, you can get a driver's licence." Nobody is uncertain about turning 18.
• 仕事が終わったら、電話します。(しごとが おわったら、でんわします) — "I'll call you when work finishes."
• 家に帰ったら、手紙が届いていた。(いえに かえったら、てがみが とどいて いた) — "When I got home, a letter had arrived." With a past main clause, たら — like と — reports a discovery: the letter was already there, and finding it was the point.

Two useful set phrases ride on たら as well: 〜たらどうですか as a gentle suggestion — 医者に行ったらどうですか (いしゃに いったら どうですか, "why don't you go to a doctor?") — and 〜たらいい as advice, which overlaps with 〜ばいい but sounds more situation-specific.

5. なら — "if that's the case"

Formation: attach なら to a noun, a な-adjective stem, or a plain-form clause. 学生なら, 静かなら, 安いなら, 日本に行くなら, 行かないなら. Crucially there is no だ before it — ×学生だなら is wrong. In writing you may see the longer ならば; the meaning is identical.

なら is the odd one out, and the cleanest way to think about it is that it is barely a conditional at all — it is closer to a topic marker. It takes something already in the air, usually something the other person just said, and builds a comment on it. That is why it so often appears as the second turn of a conversation:

• A: 来月、日本に行きます。(らいげつ、にほんに いきます) — "I'm going to Japan next month." / B: 日本に行くなら、京都がいいですよ。(にほんに いくなら、きょうとが いいですよ) — "If you're going to Japan, Kyoto is good." B is not speculating about whether A will go; A already said so.
• 寿司なら、駅前のあの店がおいしいです。(すしなら、えきまえの あのみせが おいしいです) — "If it's sushi you're after, that place by the station is good." Here なら is doing almost exactly the work of は: "as for sushi…".
• 安いなら買います。(やすいなら かいます) — "If it's cheap [as you say], I'll buy it."

The time-order twist. なら is the only one of the four where the main clause can happen before the condition. Compare these two, which are both correct and mean different things:

• お酒を飲むなら、車で来ないでください。(おさけを のむなら、くるまで こないで ください) — "If you're going to drink, don't come by car." The not-driving comes first, before any drinking.
• お酒を飲んだら、運転しないでください。(おさけを のんだら、うんてん しないで ください) — "If you've been drinking, don't drive." Here the drinking has already happened.

That pair is the single clearest demonstration of what separates なら from たら, and it is worth saying both out loud a few times until the difference feels physical rather than theoretical.

6. All four, side by side

A quick way to test yourself: take one English sentence and ask which relationship it encodes. "If you push it, it falls" — automatic, so と. "If it were cheaper, I'd buy it" — hypothesis, so ば or たら. "Call me when you arrive" — specific event plus a request, so たら. "If you're buying a laptop, buy this one" — reacting to a stated plan, so なら. Four questions, four answers, no guessing.

7. ても — the neighbour that means "even if"

Sitting right next to the conditionals is the concessive ても, which flips the logic: instead of "if A, then B", it says "even if A, B anyway". It is built on the て-form you already know, so it costs almost nothing to add. Verbs: 降る → 降っても, 行く → 行っても, 食べる → 食べても. い-adjectives: 高い → 高くても. Nouns and な-adjectives: 学生でも, 静かでも. After a voiced て-form the も becomes も after で — 飲んでも, 読んでも.

• 雨が降っても、行きます。(あめが ふっても、いきます) — "I'll go even if it rains." Compare 雨が降ったら、行きません — same first clause, opposite logic.
• 高くても買います。(たかくても かいます) — "I'll buy it even if it's expensive."
• With a question word, ても becomes "no matter what/who/how much": 何を言っても聞きません。(なにを いっても ききません) — "No matter what I say, he won't listen." いくら食べても太りません。(いくら たべても ふとりません) — "No matter how much I eat, I don't put on weight."
• The permission pattern 〜てもいいですか is the same grammar wearing a different hat: 写真を撮ってもいいですか。(しゃしんを とっても いいですか) — literally "is it fine even if I take a photo?", i.e. "may I take a photo?"

8. Mistakes learners actually make

1. と + a request. The number one error, and the reason section 2 spends so long on it. If the main clause contains ください, ましょう, 〜たい, or an order, と is wrong. Swap in たら.
2. ×行くたら. たら attaches to the past form. Build 行った first, then add ら. The same slip produces ×食べるたら and ×高いたら (correct: 食べたら, 高かったら).
3. ×学生だなら. なら follows the bare noun: 学生なら. Meanwhile と needs that だ (学生だと) and たら needs the past (学生だったら). The three behave differently after nouns, which is worth a minute of drilling.
4. Confusing たら with なら on time order. 日本に行ったらお土産を買います = I'll buy souvenirs after I get there. 日本に行くならお土産を頼みます = if you're going, I'll ask you to bring something back — the request happens before the trip.
5. Sprinkling もし everywhere. もし is an optional adverb that signals "hypothetically", and it pairs with たら or ば. It does not belong with a factual と-sentence, and adding it to a "when it happens" たら (×もし仕事が終わったら) makes a certainty sound doubtful.
6. Mixing up 〜たら with 〜たとき. With とき ("when"), the tense of the preceding verb tells you the order relative to the main clause: 日本へ行くとき、カメラを買いました means I bought the camera before leaving, while 日本へ行ったとき、カメラを買いました means I bought it after arriving. たら always means "after".
7. Forgetting that ば has a negative you'll use daily. なければならない is not an exotic pattern — it's how Japanese says "must". Learners who skip the ば chapter end up unable to build the single most common obligation form in the language.

9. What to learn first, and where these show up

A practical order, based on how much each form pays back per hour invested. First, たら. The formation is free once you know the past tense, it has no restrictions, and it handles both "if" and "when". You can survive a long time on たら alone and sound perfectly natural. Second, と, in its recognition role: you need it to read directions, appliance manuals and station signs, and you need to know why you can't put a request after it. Third, ば, approached through its fixed patterns rather than as free-form grammar — なければならない, 〜ば〜ほど and 〜ばいい are worth more than the abstract rule. Last, なら, which clicks fastest through dialogue practice, because its whole function is responding to what someone else said.

On the exam side, all four sit in beginner-to-intermediate territory. と and たら appear from N5, and ば and なら are standard N4 material; by N3 the test assumes you can already tell them apart and moves on to derived patterns such as 〜ないと, 〜たところで and 〜ものなら. The grammar sections of the exam love minimal pairs — a question will give you one sentence and four conditional endings, and the correct answer usually turns on exactly the request restriction described above. Working through the JLPT module level by level puts the vocabulary of those example sentences in place, which matters more than it sounds: most people who miss a conditional question actually missed a verb.

For practice that sticks, don't drill the forms in isolation. Take twenty verbs you already know — pull them from your review deck or a word list — and write the same sentence four ways, then decide which of the four is actually usable. Half the time three of them will be wrong, and noticing why is the whole lesson. Pair that with a short study session on the vocabulary in this guide, and run a quiz over the same set to catch anything still unfamiliar. If particles are still shaky underneath all this — が versus は in the two clauses trips people up as often as the conditional itself — the particles guide is the right thing to read next.