い-Adjective ければ

    • Adjective
    Adding 〜ければ to the end of an い-adjective makes it conditional, similar to using "if" or "when" in English.

    Table of Contents

    The Basics

    When an い-adjective ends in 〜ければ, it is said to be in the "conditional form". We use this form in the same sort of situations as we would use "if" or "when" in English. Although it’s widely used in casual conversations, 〜ければ is also appropriate in formal settings and in writing.

    Forming 〜ければ

    To attach 〜ければ to an い-adjective, simply drop the final 〜い from the adjective and then add 〜ければ. This works with both positive and negative adjectives.

    positive (cute):   かわい + ければ → かわいければ (if cute)
    negative (not cute): かわいくな + ければ → かわいくなければ (if not cute)

    All い-adjectives conjugate this way. Just don't forget that the stem form of いい (good) is よ, so its conditional form is よければ.

    Sentence Structure

    When 〜ければ is used in a sentence, you can separate the sentence into two distinct parts: the condition and the result. Usually, the conditional part of the sentence (marked with 〜ければ) comes before the result.

    • おいしければ、売れるでしょう。
    • If it's delicious, it will sell well.

    In spoken Japanese, the conditional part sometimes follows the result. This gives the impression that the condition is some kind of afterthought.

    • 売れると思うよ…おいしければ
    • I think it will sell well… if it’s delicious, that is.

    Uses

    〜ければ for General Truths

    We can use 〜ければ to point out something that definitely happens under a certain condition. Basically, we are saying that "when this thing is true, this other thing will definitely happen." For this reason, the sentence is never used in the past form—since universal truths are true all the time.

    In this use, we are talking about general facts, or things that are believed to be facts by the person speaking. So 〜ければ is commonly used in proverbs, which makes sense when we consider that proverbs generally express things that are taken to be universally true:

    • 終わりよければ全てよし。
    • All's well that ends well.

    〜ければ for Habits

    〜ければ can also be used to talk about repeated actions that happen—or happened—under a certain condition.

    • 天気がよければよく外を走ります。
    • I go for a run outside every day, if the weather's nice.

    In this example, the condition is nice weather. Whenever this condition arises, the habit is inevitable (I go jogging).

    This also works in the past, so we can use this form to talk about past habits in exactly the same way. Let's look at the jogging example again, but imagine that you don't go jogging anymore:

    • 子供のころは、天気がよければよく外を走りました。
    • When I was a child I used to go for a run outside every day, if the weather was nice.

    Notice that here we have to change the tense in both parts of the sentence in English, whereas in Japanese it's only the second part of the sentence that changes to the past tense, marked by 〜ました.

    In more old-fashioned—and written—Japanese, it's common to add ものだ to the end of the second part of the sentence:

    • 天気がよければよく外を走ったものだ。
    • I used to go jogging every day, if the weather was nice.

    This use of ものだ emphasizes the fact that we are recalling the "old days."

    Beyond the Basics

    〜ければ for Future Uncertainty

    So far, we've seen how 〜ければ can be used to talk about things that are definitely true in the present and the past. But what if we want to talk about things we're not sure about? In Japanese, we can still use this form, and we can add words like もし, だろう, でしょう, に違いない, はずだ, or かもしれない to make it clear that we are not 100% sure that the condition will happen in the first place. Depending on the words that are added, we may not be sure of the result either.

    • 天気が悪ければ、遠足は中止になる。
    • If the weather's bad, the excursion will be cancelled.
    • もし天気が悪ければ、遠足は中止になるかもしれない
    • If the weather's bad, the excursion will probably be cancelled.

    〜ければ for Intentions and Future Wishes

    To talk about something we intend to do, we can also use 〜ければ, this time adding つもり on the end of the second part:

    • 質が良ければ、買うつもりです。
    • If it's good quality, I plan to buy it.

    This also works with 〜ましょう, the Japanese equivalent of "let's".

    • 質が良ければ、買いましょう
    • If it's good quality, let's buy it.

    Common Mistakes

    い-Adjective Look-Alikes

    The noun form of some verbs look like い-adjectives. For example, 違 (to be different/incorrect) becomes 違(difference/error) in its noun form. Since 違い looks like an い-adjective, you might be tempted to use 〜ければ when you want to make it conditional. However, since 違う a verb, it requires a different way of forming the conditional.

    • ❌ 違ければ、言ってください。
      ⭕ 違えば、言ってください。
    • If it’s different/incorrect, please tell me.

    This mistake is not limited to Japanese learners. You will sometimes see younger native Japanese speakers using 違い like an い-adjective quite, both intentionally and unintentionally.