The Ultimate Guide To The Japanese Conditional Form

When you learn Japanese you'll focus at first on learning words and making simple sentences, rather than on the Japanese conditional form.

However, at some point, you will need (and probably want!) to expand your abilities to introduce nuance into your sentences. It can feel very limiting to be trapped with only the ability to say basic phrases or use the simple present and past tenses.

The Japanese conditional form is a fantastic way to level up your Japanese language ability, and the good news is that it only requires your basic knowledge of verb conjugation—which you’ve already been practicing from the very beginning!

By the way, if you want to learn Japanese fast and have fun while doing it, my top recommendation is Japanese Uncovered which teaches you through StoryLearning®. 

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What Is The The Japanese Conditional Form?

In any language, a “conditional” is a word, phrase, or construct that places a condition upon the sentence—big surprise, right?

What this means in practice is that conditionals are what are responsible for creating “if > then” ideas or introducing the concept of “if” in general.

The word “conditional” means that one part of the sentence is contingent upon (or conditional based upon) the rest of the sentence.

For example, “If I eat that whole pie, I’ll be full.” The part about being full is conditional based upon the rest of the information—that it’ll only happen if you eat a whole pie. 

Conditionals can be used to express statements like this, as well as to describe how some actions influence other actions or how events in the past have shaped the present.

Using conditional sentences, you can also talk about hypothetical situations or the context that determines the choices that you make. 

Are Japanese Conditionals The Same As In English?

The short answer is not really.

In English, the word “if” does a lot of the heavy lifting when it comes to creating conditional constructions; everything from “If he goes, so will I” to “This wouldn’t have happened if I had just gone home straight away” are all predicated upon that ever important word: if.

In Japanese, it’s not quite as simple as just introducing a single word. Instead, you need to use a variety of Japanese verb conjugations or particle + additions to convey this idea.

The good news is that while that means a bit more learning on your part right at the beginning, you don’t have to worry about shifting around the word order of the sentence (like you would in English). Just conjugate or add correctly and off you go!

The Use Of と To As A Conditional Particle

When it comes to the Japanese conditional form, one of the biggest influencers is the oft-unnoticed particle to. Simply add to after your base verb form to convey a variety of ideas:

Constant Results 

• 春になると桜が咲さきます。
  • Haru ni naru to sakura ga sakimasu.
    • Once it becomes spring, the sakura flowers bloom.

Actual Conditions 

• 雨が降と涼しくなります。
  • Ame ga furu to suzushiku narimasu.
    • It’s cooled down since the rain started.

Sequential Actions In The Past

• 新幹線に乗ると富士山が見えました。
  • Shinkansen ni noru to Fujisan ga miemashita.
    • After I got on the shinkansen, I was able to see Mt. Fuji.

In all of the situations above, you can see that the base form of the verb (which ends in -ru or sometimes -u) remains as it is, unconjugated. It is then followed by to before introducing the part of the sentence that is based upon the first statement. 

In the majority of cases, you can think of “base verb + to” as “because of X,” and the rest of your sentence becomes “Y happened.” Like so:

• 雨が降ると
  • Ame ga furu to
    • Because of the rain

• 涼しくなります。
  • Suzushiku narimasu.
    • Cooling down happened.

Expressing Hypotheticals Using -Eba

Hypotheticals are your most common “if” scenario. These are the sentences that propose an idea that has not yet been realized or come to pass.

For example, “If I throw this ball too hard, it will go over the wall.” The ball hasn’t been thrown yet; this event has not yet been realised in the scope of reality.

In order to achieve this type of construct in Japanese, you can conjugate your verb using –eba.

For -ru Verbs:

-Ru verbs tend to be fairly simple to conjugate, and the conditional is no exception. Simply replace the stem –ru with –reba instead!

• １０時まで寝れば、遅くなる！
  • Juuji made nereba, osoku naru!
    • If you sleep until 10, you’ll be late!

Consider how other -ru verbs conjugate for practice:

• Taberu (to eat) > Tabereba
• Kuru (to come) > Kureba
• Toru (to take) > Toreba

For -u Verbs:

–U verbs, as normal, follow different rules than their –ru counterparts. In this case, simply replace that final “u” sound with –eba instead!

• 薬を飲めば、はやく直るね。
  • Kusuri wo nomeba, hayaku naoru ne.
    • If you take the medicine, you’ll get better in no time!

In the example above, you haven’t taken the medicine yet—but if you did, you’d probably feel better!

More examples of –u verb conjugation for hypotheticals include:

• Oyogu (to swim) > Oyogeba
• Kaku (to write) > Kakeba
• Hanasu (to talk) > Hanaseba

Adjectives Work With -Eba Too!

That’s right! Your ability to use hypotheticals is not limited only to verbs – it works with Japanese adjectives too.

For -i adjectives, replace the last い (i) with ければ (kereba), like so:

• Oishii (delicious) > Oishikereba
• Samui (cold) > Samukereba
• Atsui (hot) > Atsukereba

For -na adjectives and nouns, you can simply attach であれば (de areba) in the same way that you would attach ではない (de ha nai) or じゃない (ja nai) to make the utterance negative.

• Genki (energy) > Genki de areba (If I/you etc were full of energy…)
• Kirei (beautiful) > Kirei de areba (If it were beautiful…)
• Ningen (human) > Ningen de areba (If I/you/he/she were human)

Using -tara To Express Variability

The verb conjugation -tara is a great way to create if > then phrases in Japanese, and it’s simple to create to boot! You already know how to make Japanese past tense, right?

In informal Japanese, your past tense will always end with –ta or –da, like this:

• Tabeta (ate)
• Nonda (drank)
• Oyoida (swam)
• Neta (slept)

From here, all you have to do is add a simple –ra on the end and you’ve created this conjugation! 

• Tabetara
• Nondara
• Oyoidara
• Netara

In the same order as “if…then,” your –tara phrase should come first in your sentence.

• 暇だったら、彦根に行こう？
  • Hima dattara, Hikone ni ikou?
    • If I’m free, you wanna go to Hikone?

• 寒くなったら、鍋 料理を食べたい。
  • Samukunattara, naberyouri wo tabetai.
    • If it gets cold, I want to eat hot pot.

Being Specific/Describing Consequences Using Nara

In some situations, it is the context that determines whether something happens. These scenarios are called contextual conditionals; they refer to times when you are being specific that in this particular situation only, “if X, then Y.” 

For example, saying “If it gets cold, I want to eat hot pot” can be interpreted two different ways depending on which conditional you choose.

Using –tara, as described above, means something along the lines of “whenever it gets cold, I feel like eating hot pot.” This is a generalized statement to describe your overall sentiment. You like eating hot pot whenever the weather starts getting chilly.

Consider how the meaning changes if we use nara.

• 寒くなるなら、鍋 料理を食べたい。
  • Samukunaru nara, naberyouri wo tabetai.
    • If it gets cold, I want to eat hot pot.

On paper, the translation doesn’t change. But the implication does—now you’re saying, “Specifically right now, you are asking me what I want to eat. At this moment, I want to eat hot pot, but only if it gets cold outside. Otherwise, I have a different answer.”

Nara is tied to very specific circumstances, and –tara is a generalized “if > then.”

• ケンが行くなら、僕も行く。
  • Ken ga iku nara, boku mo iku.
    • If Ken goes, I’ll go too.

In this example too, you can see the difference; it’s not true (at least probably!) that you’ll go everywhere that Ken goes all the time. However, in this particular instance, if (and only if) Ken goes will you go as well. Your “if” is predicated on this specific situation.

Japanese Conditional Form FAQ

Experiment With The Japanese Conditional Form

The reality is that learning any language takes time and practice—which includes immersion. Just throw yourself out there and give the Japanese conditional form a try!

To support you in the process, use the StoryLearning® method so you can learn Japanese grammar through stories, not rules.

It may be easiest to pick one type of Japanese conditional form and start to incorporate that into the way that you speak. As you become more familiar with it, you can start to add in the others until things seem natural.

Don’t give up; the building blocks that you’re laying down right now are forming the foundation of a house that you can use for years to come!

Olly Richards

Creator of the StoryLearning® Method

Olly Richards is a renowned polyglot and language learning expert with over 15 years of experience teaching millions through his innovative StoryLearning® method. He is the creator of StoryLearning, one of the world's largest language learning blogs with 500,000+ monthly readers.

Olly has authored 30+ language learning books and courses, including the bestselling "Short Stories" series published by Teach Yourself.

When not developing new teaching methods, Richards practices what he preaches—he speaks 8 languages fluently and continues learning new ones through his own methodology.