Verb［ない］+ な + そう + だ vs. 寝れなさそう

Japanese
#1

Greetings!

My apologies if this topic was already talked about. I didn’t seem to find exactly what I was thinking, but please correct me if I’m wrong.
Also, I wasn’t sure whether to register this as a bug/typo or as a question, but this is the second time I’ve noticed this, so here I am.

Like the title says, I had question about the difference between these two grammar examples.

Element 1 comes from そう.

Element 2 comes from an example phrase from せいで.

Here is the phrase in question:
犬の手術の事が心配なせいで今日は寝れなさそう。

Now, from my understanding, 寝れなさそう here is a verb.
The passive/potential form of 寝る, 寝れる. In negative, 寝れない.

Looking at the そう grammar point, I would be inclined to think that this would be like so:
寝れなそう, from 寝れない (ない removed) + な + そう.

However, as seen in the example phrase, there is an added さ between な and そう.
This makes it seemingly more akin to the そう negative form used for [い] and [な] adjectives, as in there is an added なさ + そう.

May I request some insight into why this is the way it is?

With my thanks,
Cheers!

#2

Hey! Welcome to the forums!

When ～そうだ is used with ない, it’s a bit of a special case. Instead of dropping the い and adding そう (like you normally would with an adjective), ない is first turned into its noun-like form なさ, and then combined with そう.

So, なさそう is correct, while なそう would sound unnatural.

This same rule also applies to いい, which becomes よさそう.

1 Like
#3

Hello! My thanks for the welcome and the reply! :slight_smile:

Just to make sure I understand what you’re saying correctly, would that mean that the structure examples showed in the ‘Structure’ section of そう, in the Negative subsection, the verb and [い] adjective examples would be flipped in this particular case?

Here is a screenshot to illustrate:
image

Forgive me if my question is unclear, English is not exactly my first language.

#4

Your question was interesting to me so I dug a bit deeper.

If you check out the online resources on the ~そう page, there is a link to a Self Taught Japanese article.
https://selftaughtjapanese.com/2018/06/14/the-correct-way-to-describe-a-negative-state-using-そう-sou-なさそう-vs-なそう-nasasou-vs-nasou/

The entire article is a good read, but this portion at the very end was helpful.:

" Fortunately, there is one rule you can remember instead of remembering all of the above four.

Rule: If you can safely put the wa or ga particle before ない (nai), then use なさそう (nasasou), otherwise use なそう (nasou).

Examples:

  • おいしくはない (oishiku wa nai)
    • This is a well-formed sentence so we use おいしくなさそう
  • 勉強しはない (benkyou shi wa nai)
    • This is not a well-formed sentence (it isn’t grammatically correct), so we use 勉強しなそう
  • そうじゃない＝＞そうではない (sou de wa nai)
    • There there is already a “wa” particle in this sentence before the ない, so we use そうじゃなさそう"
#5

勉強しなそう sounded really weird to me (I’ve never heard it before) so I asked a native speaker. She thought it sounded weird too.
Just stick to なさそう [i.e. 勉強しなさそう] for everything and you’ll be fine…

1 Like
#6

This does seem to contradict the lesson. I was taught early on to treat ない like an い-adjective when it came to conjugations, so it makes sense in this case that it would logically become なさそう rather than なそう。I don’t see how the “insert a は” rule would apply here.

It might also be easier if instead of subtracting ない and changing it, it was made more clear that what’s happening is you’re removing the い and replacing it with a さ (like you would if you were making a noun out of an い-adjective, ie 大きさ or 高さ). I feel like the way it’s written almost makes it look like you’re inserting a particle な and then a さ, rather than the more logical progression (for me, anyway) of さ is making ない work like a noun here.