Polite or casual?


Is this sentence polite or casual? Or even better. Is it correct to use this
casual type of sentences inside another more polite? This is the sentence:

> 時間が **なかったから** パーティーに行きませんでした。

Wouldn't it be more correct written this way?

> 時間が **ありませんでしたから** パーティーに行きませんでした。

Thank you very much.




Both sentences have minor issues even though they may be considered good in
Japanese as a foreign language. At least, both are grammatical.

「から」 actually sounds more casual/informal than many J-learners seem to think.
That is the impression that I get from speaking to them. The more formal words
with the same meaning would be 「ので」 and 「ため/ために」.

With 「です/でした」, which is not particularly polite or formal as some learners
seem to think but, nonetheless, is on the politer side, you would want to
avoid using 「から」.

In both of your sentences, 「から」 and 「でした」 are used in combination, which is
what I called an issue at the beginning.

One more thing. You would sound nicer and more apologetic if you used 「行 **け**
ませんでした」 than if you used 「行 **き** ませんでした」. Former means "I was unable to ~~"
while the latter means "I did not ~~".

Thus, the sentence that I would recommend is:

> 「時間がなかったので、行けませんでした。」

Your second sentence sounds too polite in an awkward way, using 「ありませんでした」 in
the sub-clause when the main clause contains a 「行きませんでした」. That is a little
too much for a short sentence like that.

