Conditional Forms条件形
Japanese has four conditional forms: ば (general condition), たら (temporal/discovered), なら (topic/hearsay), and と (automatic/habitual result). English collapses all of these into "if/when," but each Japanese form carries distinct nuance. Choosing the wrong one is a very common intermediate-level mistake.
Japanese has four conditional forms: ば (general condition), たら (temporal/discovered), なら (topic/hearsay), and と (automatic/habitual result). English collapses all of these into "if/when," but each Japanese form carries distinct nuance. Choosing the wrong one is a very common intermediate-level mistake.
ば form (仮定形) — general condition
The ば form expresses a general or hypothetical condition. It focuses on the condition itself and works best for universal truths, advice, and "if only" statements.
Formation
Godan: change the final kana to え-row and add ば: 行く→行けば, 話す→話せば, 読む→読めば. Ichidan: drop -ru, add -れば: 食べる→食べれば, 見る→見れば. する→すれば, 来る→来れば (kureba). い-adjectives: drop い, add ければ: 高い→高ければ. な-adjectives/nouns: add であれば or なら(ば).
Key usage
Best for advice, general truths, and hypotheticals: 練習すれば上手になる (If you practice, you’ll improve). 安ければ買う (If it’s cheap, I’ll buy it). Restriction: The ば clause generally cannot be followed by a volitional or request in the main clause when the subjects are different. You can’t say ✗ 雨が降れば傘を持っていってください.
たら form — temporal / discovered
たら is the most versatile conditional. It means "when X happens" or "if X happens" and works in almost any context.
Formation
Take the past tense (た form) and add ら: 行った→行ったら, 食べた→食べたら, した→したら, 来た→来たら (kitara). い-adjectives: 高かった→高かったら. な-adjectives/nouns: だった→だったら.
Key usage
たら is the safest "if/when." It works for future conditions (雨が降ったら行かない — if it rains I won’t go), past discoveries (家に帰ったら猫がいた — when I got home, there was a cat), and hypotheticals (宝くじに当たったら何を買う？ — if you won the lottery, what would you buy?). Unlike ば, you can freely follow たら with requests and volitional: 駅に着いたら電話してください.
なら form — topic / hearsay
なら responds to information just received or a topic brought up by someone else. It means "if (what you said is true) then..." or "if we’re talking about X, then..."
Formation
Attach なら to the plain form of verbs, adjectives, or nouns: 行くなら, 高いなら, 学生なら. The longer form ならば is more literary. のなら and んなら add emphasis to the condition.
Key usage
Responds to context: A says "I’m going to Kyoto." B says: 京都に行くなら、金閣寺に行った方がいい (If you’re going to Kyoto, you should visit Kinkakuji). なら works backwards — the condition (going to Kyoto) is already decided or stated, and the speaker adds advice. This is the only conditional where the result can precede the condition temporally.
と form — automatic / habitual result
と expresses automatic, inevitable, or habitual results. "When X, Y always/naturally happens."
Formation
Dictionary form + と: 押すと (if you push), 春になると (when spring comes). Negative: ないと (if not). Cannot use past tense before と.
Key usage
Best for natural consequences, instructions, and habitual results: このボタンを押すと電気がつく (If you press this button, the light turns on). 春になると桜が咲く (When spring comes, the cherry blossoms bloom). Restriction: Cannot be followed by volitional, imperative, or request forms. ✗ 右に曲がると止まってください — use たら instead.
Which conditional should I use?
When in doubt, use たら — it’s the most flexible and least likely to be wrong. Use ば for advice and hypotheticals. Use と for natural/automatic results and instructions. Use なら when responding to someone’s statement or a known situation. If you follow a conditional with a request (～てください), only たら and なら work — ば and と generally cannot precede requests.
The four conditional forms compared
| Verb | ば | たら | なら | と |
|---|---|---|---|---|
| 行く | 行けば | 行ったら | 行くなら | 行くと |
| 書く | 書けば | 書いたら | 書くなら | 書くと |
| 話す | 話せば | 話したら | 話すなら | 話すと |
| 読む | 読めば | 読んだら | 読むなら | 読むと |
| 食べる | 食べれば | 食べたら | 食べるなら | 食べると |
| 見る | 見れば | 見たら | 見るなら | 見ると |
| する | すれば | したら | するなら | すると |
| 来る | 来れば | 来たら | 来るなら | 来ると |
| 高い (adj) | 高ければ | 高かったら | 高いなら | 高いと |
| 学生 (noun) | 学生であれば | 学生だったら | 学生なら | — |
Example sentences
安ければ買います。
Yasukereba kaimasu.
If it’s cheap, I’ll buy it.
ば — general condition (adjective)
家に帰ったら猫がソファで寝ていた。
Ie ni kaettara neko ga sofa de nete ita.
When I got home, the cat was sleeping on the sofa.
たら — past discovery
日本に行くなら、春がおすすめだよ。
Nihon ni iku nara, haru ga osusume da yo.
If you’re going to Japan, I recommend spring.
なら — responding to stated plan
このボタンを押すとドアが開きます。
Kono botan o osu to doa ga akimasu.
If you press this button, the door opens.
と — automatic/mechanical result
もっと練習すれば上手になるよ。
Motto renshuu sureba jouzu ni naru yo.
If you practice more, you’ll get better.
ば — advice
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 me.
たら + request — only たら allows this
Common mistakes
右に曲がると止まってください
右に曲がったら止まってください
と cannot be followed by requests, commands, or volitional expressions. Use たら when the main clause contains てください, ましょう, or an imperative.
雨が降れば傘を持っていってください (different subjects)
雨が降ったら傘を持っていってください
ば has a restriction: when the subjects of the condition and result are different, you generally cannot use volitional/request forms in the result clause. たら has no such restriction.
昨日、家に帰ると猫がいた (one-time past event)
昨日、家に帰ったら猫がいた
と is for habitual/automatic results. For a one-time past discovery, use たら. 家に帰ると猫がいる (every time I get home, the cat is there) would be correct with と.
Frequently asked questions
Which conditional should I learn first?
Learn たら first. It’s the most versatile, has the fewest restrictions, and works in almost any "if/when" situation. Once you’re comfortable, add ば for advice and hypotheticals, と for automatic results, and finally なら for responding to context.
Can I always use たら instead of the others?
Almost. たら works in about 90% of conditional sentences. However, for habitual/automatic results (spring comes → flowers bloom), と sounds more natural. For responding to someone’s statement, なら is more natural. And for proverbial wisdom, ば is preferred. But if you’re stuck, たら is rarely wrong.
What about もし? How does it work with conditionals?
もし (if) is an adverb that can precede any conditional to emphasize the hypothetical nature: もし雨が降ったら, もし行けば, もし暇なら. It’s optional and adds emphasis — "IF by chance..." Using もし does not change which conditional form you need.
What group does 走る belong to?