から / からだ / からです
 

Does anyone know what type-of-speech does から belong to ?

Are all of these grammatically correct sentences:

1) お金がなかったから

2) お金がなかったからだ

3) お金がなかったからです

According to A Dictionary of Basic Japanese Grammar, から, when used to indicate a reason for something, is a conjunction.

As for the sentences you wrote, I'm not a native speaker, but they look fine to me.

All are 100% acceptable in daily convos. In Japanese schools, however, you would be corrected if you used 1) as it lacks a verb (or an auxiliary verb).

They are all perfectly cromulent. The first is a sentence fragment (so not technically "grammatically correct") but you'll hear it all the time in conversation. The second is a full sentence in plain form. The third is a full sentence in polite form.

I have been reliably informed that ので sounds nicer than から, and is particularly favored in writing.

Btw, is the だ and です allowed after ので ?

2) お金がなかったのでだ

3) お金がなかったのでです

No, you can't.

Ok, thanks all for the help =D

ほんとだ！

Kyle先生、これ、どうしてですか？(◎o◎)

(1)お金がなかったからだ/です…correct

(2)お金がなかったためだ/です…correct

(3)お金がなかったのでだ/です…incorrect

「ため」「から」「ので」are all conjunctions that show a 'reason', and why is the 3rd sentence↑ incorrect?
「お金がなかったので。」is acceptable in a conversation, no?
I didn't notice the difference until I read this thread.
ふしぎです～。

「ため」「から」「ので」 certainly serve a conjunctive function but none of them are conjunctions. 「ため」 is a noun and the other two are particles.

「お金がなかったので。」 is acceptable only in casual speech. In non-casual speech, it should be followed by a phrase expressing a result or effect.

ため is a noun, so that's why ため is OK. As for からだ being OK but のでだ not being OK, I have no answer. I've always wondered if maybe ので has its roots in の＋です since inserting のです after a sentence gives a slight "explanatory" feel to what you're saying. 公園が見つけられたのです！

But that's the mere musing of a crazy non-native speaker. :)

Edit I wasn't completely off the mark! Checking my dictionary:
So its roots are actually の＋にて＞のにて＞ので I guess. Unfortunately, it destroys my theory as to what makes ので behave differently than から in that のでです is weird but からです is not.

Edit 2 Well, actually it turns out I'm at least as creative as Japanese linguists! From this book: Topics in constraint-based grammar ... - Takao Gunji - Google Books
Put me in the のだ camp!