適度に / じゃない / 国の友だち / じゃ

Hi,

1. 適度に世話をしなくてはいけないからなんでしょう。

(Talking about the reason why robot pets sell well.)

In what sense is 適度に used? Is it saying that these "pets" need only a moderate amount of care rather than a great deal of intensive care? Or does it mean that you must be gentle with them?


2.
佐藤： 映画研究会に入ろうと思うんですけど、一緒に入りませんか。
ケン： 映画研究会ですか。まあ、映画は嫌いじゃないですけどね。

My translation:

Sato: I'm thinking of joining a film appreciation society. Would you like to come along too?
Ken: A film appreciation society? Hmm, I don't really like films.

What is the purpose of じゃない in this case? (I gather it is not a negative, but I am unclear about the exact nuance.).


3. 国の友だちが遊びに来ていて

Does 国の友だち mean friends from the village / rural area where the speaker used to live / was brought up?


4. それじゃ、来月になってからじゃだめだね。

I assume this means "In that case next month will be no good" (the context is that it will not be possible to go and see a play next month because it will have finished its run).

What is the purpose of the second じゃ in this sentence?

1)
The former.

2)
That's a negative. 嫌いじゃないですけど can connote （そんなに）好きでもない in this case.

3)
Probably yes, but the kanji 国 is rarely used in that meaning nowadays. To use 故郷 (+ furigana) would be more common, I think.

4)
That's the same as ～てはだめ/いけない. The sentence can be rephrased with 今月中に行かなくちゃ/行かなきゃだめだね.

Thank you. It seems I will never properly understand the use of じゃない.

4) I understand your rephrasing, but I am a bit puzzled about how ～てはだめ would fit into the sentence as it was originally phrased (それじゃ、来月になってからじゃだめだね). What is the ～ part? I assume it cannot be から, and なって is not next to だめ so that seems not to work either.

来月になってから performs as a noun clause here. It can be considered that the predicate 見に行く is omitted from 来月になってから見に行くんじゃだめ, since it's obvious from the context. Thus, the sentence can also be rephrased with 今月中じゃなきゃだめ.

In the pattern NOUNじゃだめ = NOUNではだめ, what is で actually doing? Why not just NOUNはだめ? Is it the same では/じゃ as in じゃない?

ては/では peforms as a conditional particle as a set.
The negative てはない/ではない/じゃない and the negative てない/でない are almost the same in meaning, but は can't be omitted from this conditional ては/では.

Could you explain why you refer to this as a "conditional" particle? Edited: Oh, I guess you may mean 来月になってからじゃだめだね ~= IF it's next month THEN it's no good?

I am a bit uncertain about the connection between ては and では in this context. Is this では a version of a basic pattern ～ては where the "verb" is the copula? Is it analogous to cases like this?:

勤務時間中たばこを吸ってはいけない

ては
［連語］《接続助詞「て」＋係助詞「は」。上に付く語 によっては「では」とも》
１ 危惧・不都合などの感情をもたらす条件を仮定して示す 。…たら。「けが人が出―大変だ」「死んではなんにも ならない」

Click to expand...

ては - goo辞書

じゃ roughly means "in the case of ~". Unlike たら or なら, the clause/phrase following ては must be negative things such like だめ, いけない, 無理. So this ては/ちゃ/では/じゃ is sometimes used like a sentence final particle, e.g., あんなやりかたじゃ（あ）ね（＝あんなやり方じゃ（あ ）ダメだね/無理だね）.
And yes, では is a variation of ては as in the dictionary I quoted above. では is used also for verbs, for instance, 妊婦はこの薬を飲んではいけない.

Thanks Toritoribe, I am familiar with ～て／ではだめ／いけない／etc. when the ～ part is a full verb, but I did not at first connect this with the じゃだめ in the original sentence because there is no full verb preceding.