I don't eitherOriginally Posted by Звездочёт
Хотя, где-то он прав.
resume
In this case: "Да нет, наверное" - our "Да" expresses a shadow of doubt. It is an indicator of her instantaneous hesitations about "Would I drink coffe?"
This answer sounds less sharp as
1. "Нет / No"
or
2. "I don't need coffy / "Не нужен/надо мне кофе".
If we want to say harder "No" than in 1. and 2. we'll say:
3. "I don't need your coffe at all / "Не нужен мне твой кофе!",
Atenntion, our specification in 2. (нужен/надо) and 3. (нужен, твой) indicates two variants of emotional: either she is annoyed by him (or by his question) or she is bored to have this dialog.
According to sentenses like:
А: Земля квадратная. / The Earth is square
Б: Да нет!!! / No, it is not!!!
Our "Да" gives a bit more emotional shade for answer "Нет / No". It means "What did you say?! It is not be true! / "Да что ты такое говоришь!? Это не может быть правдой!" or more easer with slightly reproach "You are wrong".
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So our "Да / Yes" in all these cases does not have the meaning "Yes". It gives emotional only.
Да здравствует, великий могучий русский язык.