から and ので formation/conjugation differences

Question

Consider the case when から and　ので follows a noun, な-adjective, or noun-equivalent:

から：静かだから... "Because it is quiet..." (Subjective causality)

ので：静かなので... "Because it is quiet..." (Objective causality)

(Question) What causes the difference in the parts in bold above?

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Answer 1

から 'since, because' attaches to a clause, whereas で 'with (the reason being)' attaches to a noun. 静かだ is an indicative clause (ordinary sentence), so you can simply attach から, but not で.

• 静かだから
• × 静かだで

In order to use で, you have to have a noun. To do that, you use the formal noun (or nominalizer) の taking an appositive clause. In appositive clauses and relative clauses, na-adjectives take the adnominal ending ～な.

• × 静かなのから
• 静かなので