# 昨日2時間しか寝ていない/寝ていなかった



## thetazuo

彼は*昨日2時間しか寝ていない*のだから、居眠りをしたとしても無理はないだろう。

Hi. This sentence baffles me. There seems to be a conflict between 昨日 (past) and ていない (present/future). Why not say ていなかった here?
Thank you.


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## kanadaaa

This is very difficult, but I think this is due to the presence of て in 寝ていない.
Your sentence is difficult because it's negative, so let's think about the declarative sentence below:

彼は昨日二時間だけ寝て、学校に来た。

This means "After sleeping only two hours he came to school".
This て is a subordinating conjunction that temporally aligns two events.
Clearly, the sentence has two events in it: (i) 二時間だけ寝る, and (ii) 学校に来る.
て helps to strengthen the nuance that event (i) happened before event (ii).
I can't quite explain why the sentence you give really is possible, but I guess it's because this て has the function of making explicit which one of the events happened before the other, and presumably for this reason, a tense marker is redundant.

日本語文法に詳しい方、もし説明として間違っていたら遠慮なく突っ込んでください。正直自信がないので。


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## kanadaaa

Sorry, now I've thought about it again, maybe this て is part of ている (present perfect). I thought I'd try to explain but I'm really not sure after all.


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## thetazuo

Thank you, kanadaaa. 
I found a similar example as follows: 「寝不足」を英語で！睡眠不足の便利フレーズ＆その他関連表現！ | 英トピ
どうやったら8時間も睡眠時間が確保できるの？俺、昨日なんか2時間しか寝てないよ。
There is no second event here but ている is still used. Maybe it’s just that in Japanese 寝ている is preferred over 寝ていた even if we are talking about past?


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## kanadaaa

thetazuo said:


> Maybe it’s just that in Japanese 寝ている is preferred over 寝ていた even if we are talking about past?


I can't proudly say that understanding is to the point.

After thorough reconsideration, I'd like to say my original thought in #2 was correct.
This link may help: 【第１課】て形①　～て、～て…／～てから／～ています | 毎日のんびり日本語教師


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## thetazuo

Thank you again.
So can I think, for example, the second example (どうやったら8時間も睡眠時間が確保できるの？俺、昨日なんか2時間しか寝てないよ。) implies there is a second event (e.g. I just slept for two hours yesterday, so I’m too tired for today’s exam.)?


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## kanadaaa

thetazuo said:


> So can I think, for example, the second example (どうやったら8時間も睡眠時間が確保できるの？俺、昨日なんか2時間しか寝てないよ。) implies there is a second event (e.g. I just slept for two hours yesterday, so I’m too tired for today’s exam.)?


Hmm.. this is so difficult 
Maybe there are two patterns.
In 昨日なんか2時間しか寝てないよ, it's clear that 寝て(い）ない is the negative form of 寝ている.
It might be that, unlike English, the present perfect (ている) and temporal adverbials like 昨日 don't exclude each other in Japanese.
(We can't say "I have read two books yesterday").
.....I noticed after writing this immediately preceding sentence that it's possible to say "I have read two books the previous day".
Maybe 昨日 in the sentence in #6 corresponds to "the previous day" rather than "yesterday".
But sorry again, I can't explain why there is such a difference.
And the other pattern is sentences like the one I gave in #2.
Probably, your sentence in #1 is an instance of the first pattern.


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## thetazuo

Thank you again.
I found a similar question here.
Meaning of 寝てない
It seems that if we are talking about the present effect of lack of sleep of previous day, we should use ていない/ている form instead of ていなかった/ていた. Does it make sense?
Come to think of it, can we say 彼は*昨日2時間だけ寝ている*のだから、居眠りをしたとしても無理はないだろう。?


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## kanadaaa

thetazuo said:


> 彼は*昨日2時間だけ寝ている*のだから、居眠りをしたとしても無理はないだろう。?


That sentence doesn't really make sense.
But that pattern seems to be possible as long as のだ is gone and an appropriate context is available.
E.g. あいつ昨日はちゃんと寝てるから、時間通り来ると思うよ.


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## SoLaTiDoberman

thetazuo said:


> It seems that if we are talking about the present effect of lack of sleep of previous day, we should use ていない/ている form instead of ていなかった/ていた. Does it make sense?　*Yes!*
> Come to think of it, can we say 彼は*昨日10時間も寝ている*のだから、居眠りをしたとしたらおかしいだろう。?


昨日10時間も寝ている＝「昨日10時間も*寝た*」という状態で*（今）いる*
In the "ーて form," the present tense is used even it is talking about something in the past.
So I agree with #2.

彼は*昨日2時間しか寝ていない*のだから、居眠りをしたとしても無理はないだろう。
＝彼は『昨日（昨夜）の睡眠時間が２時間だったという*現在の寝不足状態*』にあるから、(今）居眠りするのは当たり前である。

参照） 彼は*昨日(昨夜）*2時間しか*寝（ら）れなかった*から(←過去）、居眠りをしたとしても無理はないだろう（←現在）。

参照）彼は*昨日*2時間しか*寝なかった*としても、居眠りをすべきでない。
In 寝なかったとしても and 居眠りをしたとしても, the past tense is used for 仮定の話を導く節.


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## thetazuo

Thank you, kanadaaa and sola. I thought だけ and しか...ない were interchangeable in most cases. This seems to be an exception. Could you tell me why だけ doesn’t work in the op example?


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## SoLaTiDoberman

彼は昨日2時間*だけ寝たに過ぎないから*、居眠りをしたとしても無理はないだろう。
彼は昨日2時間*寝ただけだから*、居眠りをしたとしても無理はないだろう。  
彼は昨日2時間*寝ているだけだから*、居眠りをしたとしても無理はないだろう。


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## kanadaaa

thetazuo said:


> I thought だけ and しか...ない were interchangeable in most cases. This seems to be an exception.


I don't think so. They are completely different.
彼は昨日2時間しか寝ていない means "It's only for 2 hours that he slept yesterday".
On the other hand, 彼は昨日2時間だけ寝ていない means "It's only for 2 hours that he *didn't* sleep yesterday".
The second pattern is possible if there is an appropriate context, but there isn't one for the sentence in #1.
Also, the causal relationship between the first clause and the second clause is incoherent.

 彼は昨日2時間だけ寝ていないから、居眠りをしたとしても無理はないだろう。
 Because only for 2 hours he didn't sleep yesterday, it's not strange at all even if he starts to sleep.

Put simply, だけ is impossible in this case because of contextual factors.


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## thetazuo

Thank you both again.


kanadaaa said:


> On the other hand, 彼は昨日2時間だけ寝ていない means "It's only for 2 hours that he *didn't* sleep yesterday".


Sorry, I didn’t express myself clearly. I mean I thought だけ... ている and しか... ていない were interchangeable, not だけ... ていない.


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## kanadaaa

thetazuo said:


> I mean I thought だけ... ている and しか... ていない were interchangeable, not だけ... ていない.


だけ... ている and しか... ていない are generally interchangeable, as you say.
But as we can expect from this,  だけ... ていない and しか... ていない are not interchangeable.


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## thetazuo

kanadaaa said:


> だけ... ている and しか... ていない are generally interchangeable, as you say.
> But as we can expect from this,  だけ... ていない and しか... ていない are not interchangeable.


But we can’t say 彼は*昨日2時間だけ寝ている*のだから、居眠りをしたとしても無理はないだろう. Is there any grammatical reason for this?


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## kanadaaa

thetazuo said:


> But we can’t say 彼は*昨日2時間だけ寝ている*のだから、居眠りをしたとしても無理はないだろう. Is there any grammatical reason for this?


Answer:


kanadaaa said:


> the causal relationship between the first clause and the second clause is incoherent.


Because he slept for 2 hours yesterday, he might start to sleep. (= 彼は昨日2時間だけ寝ているから、居眠りをしたとしても無理はないだろう。 )
Because he slept *only* for 2 hours yesterday, he might start to sleep. (= 彼は昨日2時間しか寝ていないから、居眠りをしたとしても無理はないだろう。 )
Both of these are grammatical but the first doesn't make sense.


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## thetazuo

Thank you both again!


SoLaTiDoberman said:


> 彼は昨日2時間*寝ているだけだから*、居眠りをしたとしても無理はないだろう。





kanadaaa said:


> Because he slept for 2 hours yesterday, he might start to sleep. (= 彼は昨日2時間だけ寝ているから、居眠りをしたとしても無理はないだろう。 )


I already read sola’s reply before he deleted it. Combining with Kanadaaa’s reply, it seems that the point is if we use だけ immediately after 2時間, then it no longer means “only”; if we want to say “he slept only for 2 hours”, we have to put だけ immediately after 寝ている. Am I on the right track?


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## kanadaaa

thetazuo said:


> Am I on the right track?


I think you are.
But the following should be noted:

(i) 彼は昨日2時間だけ寝*ている*から、居眠りをしたとしても無理はないだろう。
(ii) 彼は昨日2時間だけ寝*た*から、居眠りをしたとしても無理はないだろう。
(iii) 彼は昨日2時間寝*ている*だけ_*だ*_から、居眠りをしたとしても無理はないだろう。
(iv) 彼は昨日2時間寝*た*だけ_*だ*_から、居眠りをしたとしても無理はないだろう。

I think the difference between だけ and しか is that だけ can stand alone without a negative particle, while しか cannot and must always co-occur with ない.
(This indicates that だけ is inherently affirmative, which makes it possible for it to be negated, and that しか is inherently negative, which makes it necessary for it to be used with ない.)
Put differently, だけ cannot express a negative meaning unless there is ない elsewhere.

(v) リンゴだけ食べた
(vi) リンゴだけ食べなかった
(vii) リンゴしか食べた
(viii) リンゴしか食べなかった (means almost the same as (v) except that this sounds more emphatic)

The English "only" is similar to しか in this sense because it always has a negative meaning.
This can be seen in the so-called negative inversion sentences like the following (notice that both involve subject-auxiliary inversion although they aren't questions):

(ix) In *no* way do I agree with what you're saying.
(x) *Only* in this way could John earn enough money to survive.

Actually, I tried to include a translation of だけ in my 1st sentence in #17, but I couldn't because I couldn't find an English expression corresponding to the Japanese だけ.
For this reason you shouldn't think of it to be the same as the English "only".


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## thetazuo

Thank you again.


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## Flaminius

I will explain why the following does not make sense:
*彼は昨日2時間だけ寝ているのだから、居眠りをしたとしても無理はないだろう。

First, I agree with previous posts that だけ and (だけ)しか…ない make sentences quite similar in meaning:
OK 彼は昨日2時間だけ寝た。
OK 彼は昨日2時間(だけ)しか寝ていない。

Second, I note that the difference of the two becomes apparent only when clause linkage matters:
*彼は昨日2時間だけ寝たので、今朝の会議で居眠りをした。
OK 彼は昨晩2時間(だけ)しか寝ていないので、今朝の会議で居眠りをした。

As *kanadaaa* noted in #19 (iv) _supra_, you need to use だけ in a different way to make a good Japanese sentence:
OK 彼は昨日2時間寝た*だけ*なので、今朝の会議で居眠りをした。
OK 彼は昨日2時間寝た*だけ*だから、今朝の会議で居眠りをした。

Notice that all permissible sentences use the "only" words after the conjugations of the verb 寝る.  I will list all of them; しか寝ていないので, 寝ただけなので, and 寝ただけだから.  Apparently the first construction needs both elements in order to express what other two sentences mean.  Thus, I think it is safe to say that this construction is placed both before and after the verb.

Third, and finally, I argue that the position of these words indicate what they modify.  In the exmple where clause likage fails, だけ in 2時間だけ寝た modify 2時間, an adverb.  In permissible sentences, the constructions modify something much bigger; the verb phrases or the clauses themselves including their subject nouns.  It is this structural difference that makes the paucity the reason for the second clause in permissible sentences and fails the clause likage in the sentence with だけ寝ているのだから.


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## thetazuo

Thank you for your supplementary explanation.


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