What is the difference between 「はずがない」 and 「わけがない」?


I know the following two sentences give implication that "not expecting me to
understand (it)" but I have a feeling that they give different nuances that I
just can't put my finger on:

> それは分{わ}かる **わけがない** でしょう。 _sore wa wakaru **wake ga nai** deshou._
>
> それは分{わ}かる **はずがない** でしょう。 _sore wa wakaru **hazu ga nai** deshou._

Would someone explain what is the difference of the two sentences, and also
how to choose between using はず and わけ?




disclaimer: not a native speaker

I think 'wake' implies that things happened as expected, where as 'hazu'
implies that what happened is not what was expected.

Or, 'wake' is a bit more neutral, a "matter of fact", where as 'hazu' is more
of a personal opinion/subjective kind of thing.

This is how I would understand the difference:

> それは分かるわけがないでしょう。 sore ha wakaru wake ga nai deshou.

You're not meant to understand this .. it's normal.

> それは分かるはずがないでしょう。 sore ha wakaru hazu ga nai deshou.

I see no reason you could understand this .. so what's going on?




disclaimer: not a native speaker

I think 'wake' implies that things happened as expected, where as 'hazu'
implies that what happened is not what was expected.

Or, 'wake' is a bit more neutral, a "matter of fact", where as 'hazu' is more
of a personal opinion/subjective kind of thing.

This is how I would understand the difference:

> それは分かるわけがないでしょう。 sore ha wakaru wake ga nai deshou.

You're not meant to understand this .. it's normal.

> それは分かるはずがないでしょう。 sore ha wakaru hazu ga nai deshou.

I see no reason you could understand this .. so what's going on?

