More Conditionals - ～ば

Aren't Japanese conditionals the best? Yeah! The one I'm going to look at today is the ～ば form, which can be applied to verbs, nouns, and adjectives. Here are the conjugations for it (and holy crap, there are zero exceptions - not even する or くる).

Affirmative form:

• Change the last syllable to the え equivalent and add ば
• 食べる   ->    食べれば
• 分かる   ->    分かれば
• 買う       ->     買えば
• する      ->     すれば
• くる       ->      くれば

Negative form:

•  Drop the い in ない and add ければ
• 食べない     ->    食べなければ
• 分からない  ->    分からなければ
• 買わない     ->    買わなければ
• しない          ->     しなければ
• こない          ->    こなければ

The pattern used in sentences with this conjugation is typically "Clause A ば clause B" to say "If A, then B."

Now, it's difficult to distinguish this from other conditionals, but there are a few ways. One, it's usually used when condition A results in a non-negative outcome in B. I wouldn't want to use it to say something like "If I walk, I will be late for the train," as Genki says.

Two, it's more neutral in that the "if" part in A doesn't make assumptions about the truthfulness of the condition. For example, if I were to use ば to say something like "If you're a student, you get a discount," I'm not assuming that this person is a student. I'm imply stating a result that will occur, should the condition hold true.

Three, we can kind of rule out a few scenarios where we wouldn't use it, simply based on our other conditionals. なら is context-sensitive and more like saying "given that..." And と is mostly used for stating facts or natural consequences.

With all of that in mind, I'm going to write some example sentences. I still need to read more to better understand how each of these conditionals are most commonly used.

本を読めば、合格できる。
If you read the book, you can pass the test.

映画は面白くなければ、見なくちゃよ。
If the movie isn't interesting, you don't have to see it.

早く寝れば、早く起きる。
If you go to bed early, you'll wake up early.

昼ごはんを食べなければ、家で晩ご飯を食べてもいいよ。
If you don't each lunch, you can eat dinner at my place.

Due to the aforementioned "non-negative outcome" that typically goes along with this conditional, it's also often used in giving advice. This results in clause B often being something generic like いいんですよ.

昼寝すれば、大丈夫ですよ。
If you take a nap, you'll be fine.

両親に話せれば、いいんですよ。
If you talk to your parents, it'll be fine.