Conflict among teachings of なら and ば


I recently read a helpful answer on a question asking for clarification on the
ways to say "if" in Japanese: と, たら, なら, ば. The link is here: [Differences
among -たら、なら、-んだったら、-えば,
etc](https://japanese.stackexchange.com/questions/393/differences-
among-%E3%81%9F%E3%82%89-%E3%81%AA%E3%82%89-%E3%82%93%E3%81%A0%E3%81%A3%E3%81%9F%E3%82%89-%E3%81%88%E3%81%B0-etc)

According to the post, ば has the following rule: the later clause must be non-
volitional unless a state verb like ある is used or the subjects of both clauses
are different. なら is used when saying "Since A, then B" - A is an assumed
context and B is a conclusion from A. This is supported by Tae Kim's lesson on
conditionals: <http://www.guidetojapanese.org/learn/grammar/conditionals>

However, when encountering another website's take on なら and ば, I was surprised
they grouped the two together, such that the rule on ば above applied to なら as
well. <http://www.learn-japanese-adventure.com/japanese-conditional-form-ba-
nara.html>

The only difference they seem to have stated was that ば is for verbs and
i-adjectives, whereas なら is for na-adjectives and nouns. However, negative
forms of verbs, i-adjectives, na-adjectives and nouns have ば (なければ).

  1. In that website, why did they state that なら followed the rules of ば?
  2. Why did they teach the V/i-adj and na-adj/N distinction between なら and ば?

Is there a way to resolve these conflicts?




In some sense, you can say なら is a subtype of ば. なら is ならば in its full form,
and although this word makes no sense in modern Japanese, it _did_ in olden
times. Classical ならば is but a regular inflection of なり + ば, which rightly
corresponds to today's であれば (である + ば).

So we can see that なら（ば） and ば don't really have differences in their meaning
as conditionals, and what sets them apart is actually the である part.

[code]

                + なら            + ば
    Verb        書くなら          書けば
    I-adj       重いなら          重ければ
    NA-adj      簡単なら          簡単であれば
    Noun        彼なら            彼であれば
    
[/code]

While verbs and i-adjectives can directly attach ば in their end, nouns and na-
adjectives can't inflect by themselves, so they have to be aided by copula
だ/である (~ "to be"). But the result is であれば, which has the exactly same meaning
with なら! Therefore, we don't bother to use ば with those words for most of the
time.

Only (the most of) verbs have actual difference between なら and ば. The reason
is, verbs are events bound by the time, that is, `A すれば B` is only usable when
A precedes B. なら, however, can lift this restriction by quietly nominalizing
the verb (書くなら = 書く **の** であれば). With this, you're able to frame a phrase like
乗るなら飲むな, obviously "drive" comes after "drink". It also applies to
i-adjectives, but since adjectives are states that don't have time limit, the
meaning doesn't change very much.

But yet! なら and ば _could_ make a large difference even with i-adjectives,
because of diabolical argument-omitting of Japanese. When ば directly follows a
verb or i-adjective, nothing happens. But なら can make a small seam that
enables a hidden subject (or other) to intervene, during the nominalization of
clause. That is:

> かわいければいいよ。  
>  _As long as (she) is cute, I don't care._
>
> かわいいならいいよ。  
>  [Same as above] or _As long as (you think) that (she) is cute, I don't
> care._




In some sense, you can say なら is a subtype of ば. なら is ならば in its full form,
and although this word makes no sense in modern Japanese, it _did_ in olden
times. Classical ならば is but a regular inflection of なり + ば, which rightly
corresponds to today's であれば (である + ば).

So we can see that なら（ば） and ば don't really have differences in their meaning
as conditionals, and what sets them apart is actually the である part.

[code]

                + なら            + ば
    Verb        書くなら          書けば
    I-adj       重いなら          重ければ
    NA-adj      簡単なら          簡単であれば
    Noun        彼なら            彼であれば
    
[/code]

While verbs and i-adjectives can directly attach ば in their end, nouns and na-
adjectives can't inflect by themselves, so they have to be aided by copula
だ/である (~ "to be"). But the result is であれば, which has the exactly same meaning
with なら! Therefore, we don't bother to use ば with those words for most of the
time.

Only (the most of) verbs have actual difference between なら and ば. The reason
is, verbs are events bound by the time, that is, `A すれば B` is only usable when
A precedes B. なら, however, can lift this restriction by quietly nominalizing
the verb (書くなら = 書く **の** であれば). With this, you're able to frame a phrase like
乗るなら飲むな, obviously "drive" comes after "drink". It also applies to
i-adjectives, but since adjectives are states that don't have time limit, the
meaning doesn't change very much.

But yet! なら and ば _could_ make a large difference even with i-adjectives,
because of diabolical argument-omitting of Japanese. When ば directly follows a
verb or i-adjective, nothing happens. But なら can make a small seam that
enables a hidden subject (or other) to intervene, during the nominalization of
clause. That is:

> かわいければいいよ。  
>  _As long as (she) is cute, I don't care._
>
> かわいいならいいよ。  
>  [Same as above] or _As long as (you think) that (she) is cute, I don't
> care._

