If in Japanese: Four Forms, Two Questions, One Safe Answer
Published 2026-08-27

Japanese has four ways to say if — と (to), ば (ba), たら (tara), なら (nara) — and the choice between them is part of the meaning. English says if once and leaves the rest to context. Japanese doesn't. The form you pick makes a claim about the condition itself.
Each claim is different. と (to) claims the result follows by itself, every time. ば (ba) claims a general rule. たら (tara) claims one particular occasion — this weekend, this purchase, this once. なら (nara) claims you're answering something the other person already said.
Four forms sounds like four times the homework. It isn't. Two questions sort nearly every sentence, and the sentences they can't sort have a form waiting to catch them. That's the whole grammar: four forms, two questions, one safe answer.
One boundary before we start. The ば (ba) form is not one of the eight basic verb forms — that grid of tense, politeness, and negation lives in the field note on verb conjugation, along with how to tell the verb groups apart. These four don't say when something happens. They say how the condition binds the result.
How to say if in Japanese: four forms, and why the choice matters
A dictionary translates all four Japanese conditionals as if, so the dictionary can't tell them apart. The sentences can. Watch what happens when one first half meets two different forms — spring is the condition in both lines below.
春になると、桜が咲きます (haruninaruto,sakuragasakimasu)
When spring comes, the cherry trees bloom.
春になったら、公園を散歩します (haruninattara,kouenwosanposhimasu)
When spring comes, I'll take walks in the park.
Same spring, different claim. The と (to) line states what the season does on its own — nobody decides anything, and the blossoms don't ask permission. The たら (tara) line is somebody's plan for one particular spring, and plans are exactly what と (to) refuses to host.
Here are the four claims in one view: what each Japanese conditional form claims, and what it allows in the second half of your sentence.
| Form | What it claims | What can follow it |
|---|---|---|
| 〜と (~to) | The result is automatic: machines, rules, directions | Facts only — no intention, request, or invitation |
| 〜ば (~ba) | A general condition and what follows from it | Your own plans only when the first half is a state |
| 〜たら (~tara) | One particular occasion — the widest of the four | Anything at all: the safe default |
| 〜なら (~nara) | Something already said, taken as given | Anything, and it may happen before the condition |
Two questions that pick the right conditional
Ask two questions, in this order. First, does the result follow by itself, with nobody deciding anything — a machine, a rule, a road? Then the form is と (to). Second, are you building on something the other person just said? Then it's なら (nara). When both answers are no, たら (tara) does the job, and it won't fail you.
ば (ba) sits beside the questions rather than inside them. When you're stating a general rule — cheaper if you wait, no charge if you spend a little more — that's ば (ba) territory, with one catch about the second half. The catch gets its own section below.
Try the questions on a real plan: you and a friend are watching the weather ahead of a Sunday outing. A movie doesn't follow from rain by itself — somebody has to propose it. And nobody has said anything to build on yet. Both answers are no, so the sentence goes to たら (tara).
日曜に雨が降ったら、映画にしませんか (nichiyouniamegafuttara,eiganishimasenka)
If it rains on Sunday, shall we make it a movie instead?
That ませんか (masenka) at the end is an invitation, and invitations are fussy about which conditional they'll live under. The endings themselves — ましょう (mashou), ませんか (masenka) — have a field note of their own, on the volitional form.
The to conditional and tara: the automatic and the one-time
と (to) is the automatic claim, and it's the simplest to build: the plain form plus と (to). It lives where results repeat without anyone's help — machines, natural laws, directions. Press the button and the drink appears; turn at the corner and the shop is on your right. That's と (to) country: the world doing what it does.
たら (tara) is the one-time claim. Take the plain past — the た (ta) form — and add ら (ra), so 待つ (matsu), to wait, becomes 待ったら (mattara). The tara form covers a single, particular if, and it puts no limit on what the second half does.
These two are the pair you meet first, at N5. ば (ba) and なら (nara) arrive at N4, and the field notes on the two grammar lists show where all four sit among their neighbors.
The limit on と (to) is strict, and it's the first thing that trips people. The second half states what happens — nothing decided, requested, or proposed gets in. Say you're seeing a friend off and you'd like a call when they arrive:
❌ 駅に着くと、電話しましょう (ekinitsukuto,denwashimashou)
⭕ 駅に着いたら、電話しましょう (ekinitsuitara,denwashimashou)
Let's call is an invitation, so と (to) throws it out; たら (tara) takes it without complaint. Anything with your will in it — a plan, a request, a wish — needs たら (tara) or one of its neighbors.
And here's たら (tara) doing its plainest work. You've found something you like and you're waiting on the price tag:
安かったら、買います (yasukattara,kaimasu)
If it's cheap, I'll buy it.
Making the forms is the quick part — choosing is the work. Here's the one verb 待つ (matsu) in all four, for reference.
| Form | Attach to | matsu becomes |
|---|---|---|
| 〜と (~to) | Plain form plus と (to) | 待つと (matsuto) |
| 〜ば (~ba) | Final sound to the え (e) row, plus ば (ba) | 待てば (mateba) |
| 〜たら (~tara) | Plain past plus ら (ra) | 待ったら (mattara) |
| 〜なら (~nara) | Plain form, or a bare noun, plus なら (nara) | 待つなら (matsunara) |
The Japanese ba form: general conditions, with one catch
The Japanese ba form claims a general condition: meet it, and the result holds. A verb's final sound moves to the え (e) row and takes ば (ba) — 待つ (matsu) to 待てば (mateba), 出る (deru) to 出れば (dereba). An い (i)-adjective drops its い (i) for ければ (kereba), so 安い (yasui) becomes 安ければ (yasukereba), and negatives all run through なければ (nakereba).
It's at home in rules of thumb and shop advice. Say you're checking out online and the cart is sitting just under the free-shipping line:
あと二千円分買えば、送料は無料になります (atonisen'enbunkaeba,souryouhamuryouninarimasu)
Two thousand yen more and the shipping is free.
Now the catch. ば (ba) presents the condition as the thing that settles the outcome, so the second half normally reports what happens — it isn't the place to announce what you've decided to do. Your own plans can follow only when the first half describes a state: having time, being free, the weather being good.
State first, plan second, and everything's fine:
天気がよければ、日曜は自転車で出かけます (tenkigayokereba,nichiyouhajitenshadedekakemasu)
If the weather holds, I'm going out on my bike on Sunday.
Put an action in the first half, though, and requests stop fitting. Say a friend has been talking about a new bag all week:
❌ 新しいかばんを買えば、見せてくださいね (atarashiikabanwokaeba,misetekudasaine)
⭕ 新しいかばんを買ったら、見せてくださいね (atarashiikabanwokattara,misetekudasaine)
買う (kau) is an action, not a state, so the request can't sit after ば (ba) — たら (tara) takes it without any fuss. One spelling slip to dodge while you're here: the い (i) really does drop, so it's 安ければ (yasukereba), not 安いければ (yasuikereba).
Two side doors are worth a look. ば (ba) plus よかった (yokatta) looks back at what you didn't do — もっと早く来ればよかった (mottohayakukurebayokatta), "I should have come earlier" — regret, not a condition on anything. And ばいい (baii) settles a matter and closes it, which suits directions but can sound curt to someone still deciding. A suggestion that leaves the choice open uses たらどうですか (taradoudesuka), coming up below.
Nara: the if that answers what someone just said
なら (nara) doesn't start from nothing: it takes up something the other person just said, or a topic already on the table, and builds your reply on it — which is why it's the form advice arrives in. Nara is filed under the conditionals, but it behaves more like an answer.
The attachment is the simplest of the four. A plain form takes なら (nara) directly, and a noun needs nothing in between at all — 傘なら (kasanara). The bare noun is where you'll hear it most, because a topic usually arrives as a single word. Someone mentions needing an umbrella before the weekend, and the price is on their mind:
傘なら、商店街の店のほうが安いですよ (kasanara,shoutengainomisenohougayasuidesuyo)
For an umbrella, the shops in the arcade are cheaper.
Nothing about the umbrella is uncertain here. It's simply the topic that was raised, taken as given, and answered. That's the なら (nara) claim — and it brings a freedom none of the other forms have: the second half may happen before the first.
One trip to a hot spring, three orders of events.
| Sentence | What happens first |
|---|---|
| 温泉に行くなら、タオルを買います (onsenniikunara,taoruwokaimasu) | Buy the towel, then go |
| 温泉に行ったら、タオルを買います (onsenniittara,taoruwokaimasu) | Go, then buy one there |
| もう温泉に行ったなら、写真を見せてください (mouonsenniittanara,shashinwomisetekudasai) | The trip is over — you have already been |
Only the なら (nara) line lets the buying happen before the going — you're answering a plan, so your advice points at the preparations. The たら (tara) line fixes the order: first the trip, then the towel. And the last line is なら (nara) on a plain past, taking up a trip that's already finished.
That same freedom is why advice to a traveler lands in なら (nara). A friend has just told you they're off to the mountains:
山に行くなら、厚い上着を持って行ってください (yamaniikunara,atsuiuwagiwomotteittekudasai)
If you're heading into the mountains, take a heavy jacket with you.
What なら (nara) can't do is mark things that come round on their own. Nobody raised ten o'clock as a topic; the clock just moves:
❌ 十時になるなら、店が開きます (juujininarunara,misegaakimasu)
⭕ 十時になったら、店が開きます (juujininattara,misegaakimasu)
In speech you'll also meet んなら (nnara), as in 行くんなら (ikunnara). It's the same word with んです (ndesu) folded in, and no more than a shade more casual.
Why tara is the safe answer, and where moshi fits
たら (tara) is the widest of the four because it claims the least. One particular occasion — nothing about rules, nothing about what's been said — so there's very little a たら (tara) sentence can get wrong. That's what safe means here — not a shortcut, just the smallest claim on the table.
Watch it rescue a sentence the other forms refuse. A friend might drop by in the afternoon, and you'd like to go out together when they do:
❌ 友だちが来れば、一緒に出かけましょう (tomodachigakureba,isshonidekakemashou)
⭕ 友だちが来たら、一緒に出かけましょう (tomodachigakitara,isshonidekakemashou)
An invitation after ば (ba) needs a state in the first half, and 来る (kuru) is an event — so the sentence fails ば (ba) and drops neatly into たら (tara). When a line breaks one form's claim, たら (tara) is usually where it ends up. That's the safety valve working.
もし (moshi) is the word English speakers go looking for, and it isn't a fifth conditional. It sits at the front of a sentence to flag that the condition is genuinely uncertain, while たら (tara), ば (ba), or なら (nara) still does the grammatical work beside it. A condition that's sure to arrive doesn't take もし (moshi) — spring comes whether you flag it or not.
Two everyday patterns are built on this same たら (tara). たらどうですか (taradoudesuka) offers advice — why not do it this way — and たらいいですか (taraiidesuka) asks for it, so the pair point in opposite directions. Among friends the suggestion shrinks to たらどう (taradou). Say a colleague has been running on empty all week:
疲れているんでしょう。今週末はゆっくり休んだらどう (tsukareteirundeshou.konshuumatsuhayukkuriyasundaradou)
You look worn out. How about taking it easy this weekend?
So the two questions from the top are the whole method. Does the result follow by itself — と (to). Are you answering what was just said — なら (nara). A general rule with a state up front can take ば (ba). And any sentence that answers neither question already has a home: put it in たら (tara), and it holds.
How do you say if in Japanese?
With one of four forms, chosen by what you're claiming. と (to) marks results that follow by themselves, ば (ba) marks general rules, たら (tara) marks one particular occasion, and なら (nara) answers something already said. Two questions pick between them — does the result follow by itself, and are you building on what was just raised. When neither settles it, たら (tara) is the safe choice.
What is the difference between tara and ba?
たら (tara) claims one particular occasion and lets anything follow — plans, requests, invitations. ば (ba) claims a general condition, and its second half normally reports what happens rather than what you've decided; your own plans fit only when the first half is a state, like having time or the weather being good. When you're not sure, たら (tara) is the wider of the two.
When do you use nara instead of tara?
When you're answering something the other person just said, or a topic already raised. たら (tara) sets up its own condition; なら (nara) borrows one from the conversation. なら (nara) also frees the order of events: 温泉に行くなら、タオルを買います (onsenniikunara,taoruwokaimasu) means you'll buy the towel before the trip, an order たら (tara) can't express.
What does moshi mean in Japanese?
もし (moshi) adds a note of by any chance to a conditional sentence. It isn't a conditional form itself — it sits at the front to signal that the condition is genuinely uncertain, while たら (tara), ば (ba), or なら (nara) does the grammatical work. Conditions that are certain to happen don't take it.
What does tara dou mean?
たらどうですか (taradoudesuka), often shortened to たらどう (taradou) among friends, is a suggestion built on たら (tara): why don't you, how about. The mirror question たらいいですか (taraiidesuka) asks someone else what you should do, and politer company stretches it to たらいいでしょうか (taraiideshouka). Who acts on the answer is what separates them.
Where Ukiyoe Japanese fits
Ukiyoe Japanese keeps five concept lessons on this ground — たら (tara) and と (to) at N5, then ば (ba), なら (nara), a comparison lesson built around the same two questions you've just used, and the advice pair built on たら (tara). Each comes backed by reviewed examples and the wrong-then-right pairs that show where a claim breaks.
The choosing itself lives in a drill on the four ifs. It gives you the first half of a sentence with the form missing — 春になる (haruninaru), blank, 桜が咲きます (sakuragasakimasu) — and asks which form holds it. Miss, and the explanation walks you through the claim you broke.