How is というなら different from なら?


[![enter image description
here](https://i.stack.imgur.com/bJ3TR.png)](https://i.stack.imgur.com/bJ3TR.png)

いい!? これからもし私たちが空へ行くというのなら....

Is there any difference if I replaced it with なら? If there isn't, is there a
sentence where it wouldn't be interchangeable?




Actually, all 行くなら / 行くというなら / 行くのなら / 行くというのなら are grammatically possible
here. I mean, grammatically allowed but each has its own meaning.

  * ～行くなら: _if we (will / are going to) go..._  
Yes, this is very straightforward. The non-past form tends to mean near
future.

  * ～行くというなら: _under the condition that we go... / if you insist we go..._  
`V というなら` is, in most cases, an idiom that means either of the following:

    1. "[an expression that tells it is okay/allowed] ... only if V"
    2. "if somebody insists to V"

However, neither of them fits well in this context.

  * ～行くのなら: _if (there is) the fact that we go... / if the one (where) we go..._  
の is a general nominalizer, accepting roughly two types of interpretation:

    1. apposition: "the fact of [predicate]"
    2. relative: "something or somebody that [predicate] / that is [predicate]-ed / with/to/from... which [predicate]"

And if we take the former understanding, it yields the convoluted first
translation above; but it is in turn, from a learner's perspective,
combination of `行く + のだ + [conditional]`, which can be practically translated
as "if we are bound/decided to go..."

  * ～行くというのなら: _if (there is) the fact that we say we go..._  
The translation is even more enigmatic now :P, but here the point is that the
extra という works in two ways. Firstly, it can eliminate the "relative" reading
from bare `V のなら` to unambiguously mean the nominalization of the action.
Secondly, it adds a little flavor of quotation という, which effectively
introduces the nuance of **subjunctive mood** i.e. mentioning a hypothetical
situation.

In conclusion, a cleaner answer would be like:

> もし私達が空へ行くなら  
>  _if we go up into the sky_

versus

> もし私達が空へ行くというのなら  
>  _if we **are supposed to** go up into the sky_  
>  or  
>  _**in the event that** we go up into the sky_

