わけがない - Grammar Discussion

English translation:
there is no reason
it is impossible

Structure:
Verb[ / ない ] + わけがない
Verb[ よう ] + わけがない
なAdj + な + わけがない
いAdj + わけがない

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I don’t really get the difference between
ないわけがない、ないわけではない and ないことはない.

How would the meaning of this example sentence change in each case?

  1. 翼があるんだから、飛べないわけがない。
  2. 翼があるんだから、飛べないわけではない。
  3. 翼があるんだから、飛べないことはない。
1 Like

@Anthropos888
Hey :grin:

わけ literally translated means “reason, meaning”.

It is used when expressed conclusion from reasoning, judgment, calculation, something just seen, something just heard, etc.

Example:
A: この時計は金からできている。This watch is made of gold. (Just heard information)
B: だから通りで重いわけだよ!No wonder it is so heavy! (conclusion from)

(there are MANY uses of this expression)

As you know, がある is used to express that something exists, and わけがない expresses that something does not exist.

So if we connect what we know about わけ and がない, it becomes clear that わけがない means that the reason for something happening does not exist. In other words, something is impossible. VERY STRONG NEGATION.
It is similar to っこない or はずがない

翼があるんだから、飛べないわけがない。
(about pidgeon for example)
It has wings, so there is no way it won’t fly. (it is impossible for it to not fly)

わけではない simply negates the reason (not the existence of it!), so it is used to deny the conclusion from reasoning, judgment, calculation, something just is seen, something just heard, etc. It is wrong to conclude something.

翼があるけど、飛ぶわけではない。(it is often used with しかし、けど、が, etc)
(about chicken for example)
It has wings, but it doesn’t mean it will fly.
It has wings, but it is wrong to conclude that it will fly.

It can be also used as a weak negation when refusing (when you want to avoid directly negating to not be rude, or to make someone feel bad):

今晩、用事ある?Do you have plans today?
用事あるわけではないけど It is not like I have plans, but…

ないこともない is a weak affirmation (by double negation).
Something along “it is possible, but not always; it is the case but not in all aspects”

翼があるんだから、飛べないことはない。
It has wings, so it isn’t the case it won’t fly.

It is very similar (if not identical) to:
翼があるんだから、飛べないわけではない。
It has wings, so it is not like it won’t fly.
(it has wings, so it is wrong to conclude it won’t fly)

ないこともない is often used with が、after which circumstances when something is not the case, are described.

この料理に肉が使えない、いや、使えないこともないが、にわとりだけ。
In this dish you cannot use meat, no, it is not the case you cannot use it, but only chicken.

(わけではない can also be used like this, but I think it’s rarer)

3 Likes

Imo, I would say:

翼があるんだから飛べないことはない(が、短い時間だけ飛べる。or someting like that).

1 Like

Great, thanks for your explanation!
So ないことはない and ないわけではない are interchangeable in most case? But using ないわけではない sounds a bit softer?

Here another example from the JLPT 2 exam:

暑い地方でも、泥と草で太陽光線を避ける家を作れば、激しくなるという _____。

  1. わけがない

  2. わけにはいかない

  3. わけだ

  4. わけではない

When I see all the different わけ together my brain just shuts off :expressionless:

So except for 3) the other answers wouldn’t make any sense at all?