I've read a number of questions on here regarding のだ, but what I'm looking for in this question is the nuance のだ imparts to a sentence as compared to when a similar construction is used. There are two usages of it by which I am particularly befuddled.

  1. When のだ is used to provide an explanation, how does it differ from (だ)から? For example, how do the following two sentences differ? (And no, I'm not asking about the difference between のだから and だから; I've found satisfactory answers on that topic.)



  2. When occurring as のだ{が/けど}, how does the sentence differ from when the の is dropped? The answer given to this question describes this usage as providing background, but can background not be provided without the の? And again, how do the following two sentences differ?

    宿題をしたですが、学校に持ってくるのを忘れました。(taken from here)


  • 1
    For the final example sentence, do you mean 宿題をしましたが... ? – mamster Jan 19 '18 at 15:03
  • @mamster Thank you for the correction. I've changed it in the question. – lightweaver Jan 20 '18 at 2:28

When のだ is used to provide an explanation, how does it differ from (だ)から?

Giving a reason is only one of the ways to explain something. Explanatory-のだ is used in broader situations to mark an important part of your conversation. When it does provide a reason for the previous sentence, it's semantically interchangeable with から. The difference is から is more explicit, unambiguous and matter-of-factly. から is preferred in logical sentences such as math proofs. In casual and/or lively conversations, から is less common. You can even combine both から and ん and say 電話が来たからなんです. This is more emphatic and vivid than plain 電話が来たからです.

And again, how do the following two sentences differ?


This is a typical explanatory-の which provides a clarification of the previous context. A sentence like this is usually used as an excuse for a question like "Why did you forget your homework?". In such cases, the first sentence should be used. Without の/ん, it doesn't sound like an excuse at all. If this was an answer to a question like "How was your last vacation?", the neutral second sentence could be fine.


I would like to show you the research of experts regarding question 1, but to me the difference is so subtle ( And on the presumption you already know んだ=のだ ). Regarding question 2, I am unable to answer because there are 2 questions.

Here, a thesis says,



から's distinctive meaning.

Now, 格助詞{かくじょし}「から」 denotes the origin, starting points. To denote starting points means the thing that started from the starting point goes to somewhere. In other words, by 「から」one has a feeling of "movement from to to" or the "shift". This fact can be applied to the connective particle. In the case of connective particle, the "starting point" would denote the "reason, and the reason "goes" "moves to" the "conclusion."

enter image description here

格助詞「AからB(まで)」 (1)自転車で駅から学校まで行く。( I go to school from station by bicycle. )

接続助詞「XからY」 (2)雨{あめ}が降{ふ}っているから出かける見合{みあ}わせよう. ( Because it is raining, let's refrain from going out. )

So your sentence


is same with the pattern (2).

And you already know the particle の "thingnifies" the preceding sentence.

And ので is consisted of の+で.

Let's move on to the role of で








>「で」's controlling function.

Now, で. で basically denotes the "place, basis or ground" and have a function to denote "limit something". Tanaka, Matsumoto defined in 1997 で’s controlling function as "Expect a movement/action while limiting the scope of the target X"

(11) When we talk about Fujisawa, this restaurant would the best

(12)Talking about Japan, it is Tokyo where the price of commodities is highest.

(13)I write a novel with a pen.

(14)I am in trouble with my research




3 The difference between から and ので

から's function.

から's controlling function is defined as ”Take the place(incident) X as the starting point of the incident Y”. When compared with ので, which is explained later, the connection between the incident X ( reason ) to the incident Y ( the result ) is very straight forward and direct. Therefore using から makes the causal relationship in the sentence more direct and clearer ( compared with ので ) so that から tends to be used to stress the causal relationship in the sentence.



ので's function.

ので’s function is 「 make the incident X thingnified ( 体言化 ), and limit the X as the reason of the incident Y 」. ので denotes the place, basis or ground, of the incident Y. When compared with から's function, which is the movement from of the reason to the result, the causal relationship is weaker. ので is used to denote when the speaker would not like to stress the causal relationship, or just to express the causal relationship subjectively.

Regarding question 2, you have 2 questions and it is a bit hard to answer.

When occurring as のだ{が/けど}, how does the sentence differ from when the の is dropped?


And again, how do the following two sentences differ?

KIndly focus only on one question because you seem to be connecting those 2 questions as if they are in relationship.

Thank you.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.